Pyrrolopyrrole derivatives, their manufacture and use

ABSTRACT

The present invention relates to compounds of the formula (I) wherein the substituents are as defined in claim  1 , and their use as organic semiconductor in organic devices, like diodes, organic field effect transistors and/or a solar cells. The compounds of the formula I have excellent solubility in organic solvents. High efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability can be observed, when said compounds are used in semiconductor devices or organic photovoltaic (PV) devices (solar cells).

The present invention relates to 1,4-diketopyrrolo[3,4-c]pyrrole (DPP)derivatives of the below formula I, wherein the substituents are asdefined herein below, to their manufacture; to their use as organicsemiconductors, e.g. in semiconductor devices, especially a sensor, adiode, a photodiode, an organic field effect transistor, a transistorfor flexible displays, and/or a solar cell (photovoltaic cell); to suchsemiconductor devices comprising diketopyrrolopyrrol derivatives of theformula I as a semiconducting effective means, and to devices containingsaid semiconductor devices.

JP 2006117591-A to Toyo Ink Manufacturing Co. disclosesdiketopyrrolopyrrol derivatives for use in organic electroluminescentelements, like flat panel displays and liquid crystal displays, but notfor use as organic semiconductors.

WO 2004/090046 A1 to Ciba discloses fluorescent diketopyrrolopyrrol(DPP) derivatives, mainly for use in inks, toners, colorants, pigmentedplastics, color changing media, solid dye lasers and electroluminescentdevices. Said DPP derivatives have a smaller or shorter side chain onboth sides of the diketopyrrolopyrrol moiety than thediketopyrrolopyrrol derivatives claimed per se in the presentspecification. In addition, specifically disclosed, i.e. individualized,compounds include only those derivatives wherein the DPP nitrogen atomsare substituted by alkyl groups having no more than 5 carbon atoms. Ashas been found by the present invention, for the overall efficiency ofphotovoltaic cells the number of carbon atoms in each of the alkylsubstituents on the DPP nitrogen atoms is of major importance and shouldbe at least 7, preferably at least 10.

It has surprisingly been found that certain monomericdiketopyrrolopyrrol derivatives, especially those having longer sidechains, can be used as organic semiconductors. Said derivatives haveexcellent solubility in non-halogenated organic solvents (allowing easyhandling). They can be synthesized easier than polymers (allowing costsavings), and they are easy to purify (allowing very pure products to beobtained at low cost).

For semiconducting devices, like solar cells, the power conversionefficiency (PCE), i.e. the percentage of power converted from absorbedlight to electrical energy, is decisive. While silicon based solar cellsreach already a PCE of up to 20%, the PCE of solar cells based onorganic semiconductors is still much lower, i.e. in the range of 5% forpolymeric semiconductors. For monomeric, i.e. small molecule basedsemiconductors the PCE, as reported before the priority date of thepresent invention, is even lower than for polymeric semiconductors.Solution processed solar cells so far were reaching a PCE just up toabout 1.3%.

Despite the lower PCE attained thus far, small molecules potentiallyoffer several advantages over polymer and silicon based materials. Withrespect to silicon based materials said advantages include lower costfabrication by solution processing, lightweight and compatibility withflexible substrates. With respect to polymeric materials small moleculesdo not suffer from batch to batch variations, broad molecular weightdistributions, end group contamination, and difficult purificationmethods. Furthermore, small molecules may display higher hole andelectron mobilities than their polymeric analogues, presumably as aresult of better molecular ordering.

The task of the present invention was the identification of smallmolecules with improved PCE, high field effect mobility (charge carriermobility), high on/off current ratio, and low threshold voltage. A highon/off current ratio is especially useful for an organic field effecttransistor (OFET).

According to the present invention it has been found that certain smallmolecules of the diketopyrrolopyrrol class surprisingly exhibitextremely high PCEs in solar cells. Some compounds exhibit PCEsexceeding 4% ! Such values have not been reported for any small moleculebefore! It should be kept in mind that these efficiencies have not evenbeen optimized. Optimisation may be effected in various ways, e.g. byvariation of the donor-acceptor ratio, e.g. to 70:30 by weight, or bycoating the anode with a very thin (5 to 10 nanometers thick) and smoothlayer of nickel oxide.

The invention relates especially to diketopyrrolopyrrol derivatives ofthe formula I

wherein R¹ and R² are independently of each other an aliphatic,cycloaliphatic, cycloaliphatic-aliphatic, aromatic, aromatic-aliphatic,heteroaromatic or heteroaromatic-aliphatic group having up to 49 carbonatoms,a and d independently of each other are 0, 1, 2 or 3,Ar¹ and Ar⁴ are independently of each other a bivalent group of theformula II or IV

whereinR⁶ and R⁷ are as defined below,p represents 0, 1, or 2,R⁵ is an aliphatic hydrocarbon group having up to 25 carbon atoms, ortwo vicinal groups R⁵ together represent alkylene or alkenylene havingup to 7 carbon atoms, it being possible that two groups R⁵ present inthe group of formula II differ from each other,b, c, e, and f independently of each other represent 1, 2 or 3,Ar², Ar³, Ar⁵, and Ar⁶ are independently of each other a bivalent groupof one of the formulae IV to X and L,

wherein R⁶, R⁷, R⁸, R⁹, R¹², R¹³, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹are independently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, or heteroaryl, or R⁶ and R⁷ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms,R¹⁰ and R¹¹ are independently of each other hydrogen, C₁-C₁₈alkyl,C₆-C₂₄aryl, heteroaryl, or R¹⁰ and R¹¹ together represent oxo or form afive or six membered ring, which is unsubstituted or substituted bya) an aliphatic hydrocarbon group having up to 18 carbon atoms,b) C₁-C₁₈alkoxy or C₂-C₁₈alkylenedioxy in both of which carbon atomswhich are not adjacent to oxygen may be replaced by oxygen, orc) C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, C₃-C₁₂cycloalkyl orC₄-C₁₂cycloalkyl-alkyl, andR³ and R⁴ are independently of each other a group of one of the formulaeXI to XIX,

wherein R²² to R²⁶ and R²⁹ to R⁵⁸ represent independently of each otherhydrogen, an aliphatic hydrocarbon group having up to 25 carbon atoms,alkoxy or alkenyloxy having up to 18 carbon atoms, halogen, acycloaliphatic, cycloaliphatic-aliphatic, aromatic, aromatic-aliphatic,heteroaromatic or heteroaromatic-aliphatic group having up to 25 carbonatoms, or a group of the formula (III)

wherein R represents an aliphatic hydrocarbon group having up to 12carbon atoms, or two groups R²² to R²⁶ and R²⁹ to R⁵⁷ which are in theneighborhood of each other, together represent alkylene or alkenylenehaving up to 8 carbon atoms, thereby forming a ring, andR²⁷ and R²⁸ are independently of each other hydrogen, C₁-C₂₅alkyl,C₁-C₁₈alkoxy, C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, or a group of theformula (III) shown above, wherein R represents an aliphatic hydrocarbongroup having up to 12 carbon atoms, or R²⁷ and R²⁸ together or R²⁷ andR⁵⁸ together represent alkylene or alkenylene which may be both bondedvia oxygen and/or sulfur to the thienyl residue and which may both haveup to 25 carbon atoms.

The general terms used above have the following meanings:

An aliphatic group having up to 49 carbon atoms, as represented e.g. bythe substituents R¹ and R², is an unsubstituted or substituted aliphatichydrocarbon group having up to 49, e.g. up to 25 carbon atoms whereinthe free valency extends from a carbon atom. Preferably, aliphaticgroups as represented by the substituents R¹ and R² have at least 7,more preferably at least 8, even more preferably at least 10, and mostpreferably at least 14 carbon atoms. An aliphatic hydrocarbon grouphaving up to 49, e.g. up to 25 carbon atoms is a linear or branchedalkyl, alkenyl or alkynyl (also spelled alkinyl) group having up to 49,e.g. up to 25 carbon atoms. Preferred are aliphatic hydrocarbon groups,like especially alkyl groups, having 7-49, especially 8-49, e.g. 7-25,especially 8-25, preferably 14-25 carbon atoms. An example of apreferred alkyl group, as represented by the substituents R¹ and R², is2-decyl-tetradecyl.

Examples for C₁-C₂₅alkyl groups are methyl, ethyl, n-propyl, isopropyl,n-butyl, sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl,3-pentyl, 2,2-dimethylpropyl, 1,1,3,3-tetramethylpentyl, n-hexyl,1-methylhexyl, 1,1,3,3,5,5-hexamethylhexyl, n-heptyl, isoheptyl,1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl,3,7-dimethyl-octyl, 1,1,3,3-tetramethylbutyl, 2-ethylhexyl,2-n-butyl-hexyl, n-nonyl, decyl, 2-hexyl-decyl, undecyl, dodecyl,tridecyl, tetradecyl, 2-decyl-tetradecyl, pentadecyl, hexadecyl,heptadecyl, octadecyl, eicosyl, heneicosyl, docosyl, tetracosyl andpentacosyl, of which 2-decyl-tetradecyl is especially preferred as ameaning of R¹ and R².

Examples for C₂-C₂₅alkenyl groups are vinyl, allyl, methallyl,isopropenyl, 2-butenyl, 3-butenyl, isobutenyl, n-penta-2,4-dienyl,3-methyl-but-2-enyl, n-oct-2-enyl, n-dodec-2-enyl, isododecenyl,n-dodec-2-enyl or n-octadec-4-enyl.

Examples for C₂₋₂₅alkynyl groups are ethynyl, 1-propyn-3-yl,1-butyn-4-yl, 1-pentyn-5-yl, 2-methyl-3-butyn-2-yl, 1,4-pentadiyn-3-yl,1,3-pentadiyn-5-yl, 1-hexyn-6-yl, cis-3-methyl-2-penten-4-yn-1-yl,trans-3-methyl-2-penten-4-yn-1-yl, 1,3-hexadiyn-5-yl, 1-octyn-8-yl,1-nonyn-9-yl, 1-decyn-10-yl, or 1-tetracosyn-24-yl.

Aliphatic groups can, in contrast to aliphatic hydrocarbon groups, besubstituted by any acyclic substituents, but are preferablyunsubstituted. Preferred substituents are C₁-C₈alkoxy or C₁-C₈alkylthiogroups as exemplified further below. The term “aliphatic group”comprises also alkyl groups wherein certain non-adjacent carbon atomsare replaced by oxygen, like —CH₂—O—CH₂—CH₂—O—CH₃. The latter group canbe regarded as methyl substituted by —O—CH₂—CH₂—O—CH₃.

A cycloaliphatic group having up to 49, e.g. up to 25 carbon atoms, asrepresented e.g. by the substituents R¹ and R², is an unsubstituted orsubstituted cycloaliphatic hydrocarbon group having up to 49, e.g. up to25 carbon atoms wherein the free valency extends from a ring carbonatom.

A cycloaliphatic hydrocarbon group is a cycloalkyl or cycloalkenyl groupwhich may be substituted by one or more aliphatic and/or cycloaliphatichydrocarbon groups.

A cycloalkyl group has at least 3, preferably at least 5 carbon atomsand is typically C₅-C₁₂cycloalkyl, such as cyclopentyl, cyclohexyl,cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl,cyclododecyl, preferably cyclopentyl, cyclohexyl, cycloheptyl, orcyclooctyl, which may be unsubstituted or substituted by one or morealiphatic and/or cycloaliphatic hydrocarbon groups and/or condensed withphenyl groups as defined herein and/or condensed with phenyl groups.

A cycloaliphatic-aliphatic group is an aliphatic group substituted by acycloaliphatic group, wherein the terms “cycloaliphatic” and “aliphatic”have the meanings given herein and wherein the free valency extends fromthe aliphatic moiety. Hence, a cycloaliphatic-aliphatic group is forexample a cycloalkyl-alkyl group.

A cycloalkyl-alkyl group is an alkyl group substituted by a cycloalkylgroup, e.g. cyclohexyl-methyl.

A “cycloalkenyl group” means an unsaturated alicyclic hydrocarbon groupcontaining one or more double bonds, such as cyclopentenyl,cyclopentadienyl, cyclohexenyl and the like, which may be unsubstitutedor substituted by one or more aliphatic and/or cycloaliphatichydrocarbon groups and/or condensed with phenyl groups.

For example, a cycloalkyl or cycloalkenyl group, in particular acyclohexyl group, can be condensed one or two times with phenyl whichcan be substituted one to three times with C₁-C₄-alkyl. Examples of suchcondensed cyclohexyl groups are groups of the formulae XX to XXIV:

in particular

which can be substituted in the phenyl moieties one to three times withC₁-C₄-alkyl.

Preferred substituents of a substituted cycloaliphatic hydrocarbon groupare e.g. C₁-C₈alkoxy or C₁-C₈alkylthio groups.

Preferably, a and d, independently of each other, are 0, 1 or 2. Alsopreferably a and d have the same meaning.

An aliphatic hydrocarbon group having up to 25 carbon atoms R⁵ is alinear or branched alkyl, alkenyl or alkynyl (also spelled alkinyl)group having up to 25 carbon atoms as exemplified above.

Alkylene is bivalent alkyl, i.e. alkyl having two (instead of one) freevalencies, e.g. trimethylene or tetramethylene.

Alkenylene is bivalent alkenyl, i.e. alkenyl having two (instead of one)free valencies, e.g. —CH₂—CH═CH—CH₂—.

A bivalent group of the formula II wherein two vicinal groups R⁵together represent alkylene or alkenylene having up to 7 carbon atoms,it being possible that two groups R⁵ present in the group of formula IIdiffer from each other, is for example a group of the formula

C₁-C₂₅alkyl as represented by R⁶, R⁷, R⁸, R⁹, R¹², R¹³, R¹⁵, R¹⁶, R¹⁷,R¹⁸, R¹⁹, R²⁰ and R²¹ has the meanings given above.

C₁-C₁₈alkoxy, as represented e.g. by R⁶, R⁷, R⁸R⁹, R¹², R¹³, R¹⁵, R¹⁶,R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹ to R²⁶, is e.g. methoxy, ethoxy, n-propoxy,isopropoxy, n-butoxy, sec.-butoxy, isobutoxy, tert.-butoxy, n-pentoxy,2-pentoxy, 3-pentoxy, 2,2-dimethylpropoxy, n-hexoxy, n-heptoxy,n-octoxy, 1,1,3,3-tetramethylbutoxy, 2-ethylhexoxy, n-nonoxy, decoxy,undecoxy, dodecoxy, tridecoxy, tetradecoxy, pentadecoxy, hexadecoxy,heptadecoxy, and octadecoxy, preferably C₁-C₄alkoxy.

The term “alkylthio group” means the same groups as the alkoxy groups,except that the oxygen atom of ether linkage is replaced by a sulfuratom.

An aromatic group as represented e.g. by R¹ and R² is preferablyC₆-C₂₄aryl. C₆-C₂₄aryl, as represented e.g. by R¹, R², R⁶, R⁷, R⁸, R⁹,R¹², R¹³, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹, is e.g. substituted orpreferably unsubstituted phenyl, indenyl, azulenyl, naphthyl, biphenyl,as-indacenyl, s-indacenyl, acenaphthylenyl, fluorenyl, phenanthryl,fluoranthenyl, triphenlenyl, chrysenyl, naphthacen, picenyl, perylenyl,pentaphenyl, hexacenyl, pyrenyl, or anthracenyl, preferably phenyl,1-naphthyl, 2-naphthyl, 3- or 4-biphenyl, 9-phenanthryl, 2- or9-fluorenyl, 3- or 4-biphenyl, which all may be unsubstituted orsubstituted, e.g. by alkyl or alkoxy.

An aromatic-aliphatic group as represented e.g. by R¹ and R² is analiphatic group which is substituted by an aromatic group, wherein theterms “aromatic” and “aliphatic” are as defined herein, e.g. an aralkylgroup, like 3-phenyl-propyl.

C₇-C₂₅aralkyl, as represented e.g. by R⁶, R⁷, R⁸, R⁹, R¹², R¹³, R¹⁵,R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²⁷, or R²⁸ is e.g. phenyl-alkyl, likebenzyl, 2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl,3-phenyl-propyl, ω-phenyl-butyl, ω,ω-dimethyl-ω-phenyl-butyl,ω-phenyl-dodecyl, ω-phenyl-octadecyl, ω-phenyl-eicosyl, andω-phenyl-docosyl, wherein the phenyl moiety may be unsubstituted orsubstituted, e.g. by alkyl, alkoxy or halogen. A preferred meaning forC₇-C₂₅aralkyl, as represented by R⁶, R⁷, R²⁷, or R²⁸ is e.g.3-phenyl-propyl.

A heteroaromatic group having up to 49, preferably up to 25 carbon atomsas represented e.g. by R¹ and R² is a heteroaryl group as defined below,but not having more than 49, preferably not more than 25 carbon atoms.

Heteroaryl, as represented e.g. by R⁶, R⁷, R⁸, R⁹, R¹², R¹³, R¹⁵, R¹⁶,R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹, is e.g. C₂-C₂₆heteroaryl, i.e. e.g. a ringwith five to seven ring atoms or a condensed ring system, whereinnitrogen, oxygen or sulfur are the possible hetero atoms, and istypically an unsaturated heterocyclic group with five to 30 atoms(including both carbon and hetero atoms) having at least six conjugatedπ-electrons, such as thienyl, benzo[b]thienyl, dibenzo[b,d]thienyl,thianthrenyl, furyl, furfuryl, 2H-pyranyl, benzofuranyl,isobenzofuranyl, dibenzofuranyl, phenoxythienyl, pyrrolyl, imidazolyl,pyrazolyl, pyridyl, bipyridyl, triazinyl, pyrimidinyl, pyrazinyl,pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl,quinolizinyl, chinolyl, isochinolyl, phthalazinyl, naphthyridinyl,chinoxalinyl, chinazolinyl, cinnolinyl, pteridinyl, carbazolyl,carbolinyl, benzotriazolyl, benzoxazolyl, phenanthridinyl, acridinyl,pyrimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl,isoxazolyl, furazanyl or phenoxazinyl, which can be unsubstituted orsubstituted, e.g. by alkyl.

A heteroaromatic-aliphatic group having up to 49, preferably up to 25carbon atoms as represented e.g. by R¹ and R² is an aliphatic groupsubstituted by an heteroaromatic group wherein the terms “aliphatic” and“heteroaromatic” are as defined herein except for the total number ofcarbon atoms which must not exceed 49, preferably 25, and wherein thefree valency extends from the aliphatic moiety, e.g. heteroaryl-methyl.

A bivalent group of the formula IV wherein R⁶ and R⁷ together representalkylene or alkenylene which may be both bonded via oxygen and/or sulfurto the thienyl residue and which may both have up to 25 carbon atoms, ise.g. a group of the formula XXIX or XXX

wherein A represents linear or branched alkylene having up to 25 carbonatoms, preferably ethylene or propylene which may be substituted by oneor more alkyl groups, and Y represents oxygen or sulphur. For example,the bivalent group of the formula —Y-A-O— represents —O—CH₂—CH₂—O— or—O—CH₂—CH₂—CH₂—O—.

A bivalent group of the formula VI wherein R¹⁰ and R¹¹ togetherrepresent oxo is a group of the formula (XXXI).

C₁-C₁₈alkoxy in which carbon atoms which are not adjacent to oxygen maybe replaced by oxygen is e.g. a group of one of the formulae—O—CH₂—O—CH₂—CH₂—O—CH₃, —O—(CH₂)₂OCH, —O—(CH₂CH₂O)₂CH₂CH₃, —O—CH₂—O—CH₃,—O—CH₂CH₂—O—CH₂CH₃, —O—CH₂CH₂CH₂—O—CH(CH₃)₂, —O—[CH₂CH₂O]_(n)—CH₃wherein n=1-10, —O—CH₂—CH(CH₃)—O—CH₂—CH₂CH₃ and—O—CH₂—CH(CH₃)—O—CH₂—CH₃.

C₂-C₁₈alkylenedioxy in which carbon atoms which are not adjacent tooxygen may be replaced by oxygen is e.g. a group of the formula—O—CH₂—O—CH₂—CH₂—O—.

An aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aromatic,aromatic-aliphatic, heteroaromatic or heteroaromatic-aliphatic grouphaving up to 25 carbon atoms as substituent R²² to R²⁶ of a group of theformula XI has the meanings defined above. A preferred group of theformula XI is the 4-biphenyl group, which may be unsubstituted orsubstituted within the scope of the above terms.

An example for alkenyloxy is e.g. 3-butenyloxy.

Halogen is fluoro, chloro, bromo or iodo.

A group of the formula XI wherein two groups R²² to R²⁶ which are in theneighborhood of each other, together represent alkylene or alkenylenehaving up to 8 carbon atoms, thereby forming a ring, is e.g. a group ofthe formula XXXII or XXXIII

wherein in the group of the formula XXXII R²³ and R²⁴ together represent1,4-butylene and wherein in the group of the formula XXXIII R²³ and R²⁴together represent 1,4-but-2-en-ylene.

A group of the formula XII, wherein R²⁷ and R²⁸ together representalkylene or alkenylene which may be both bonded via oxygen and/or sulfurto the thienyl residue and which may both have up to 25 carbon atoms, ise.g. a group of the formula XXXIV or XXXV

wherein A represents linear or branched alkylene having up to 25 carbonatoms, preferably ethylene or propylene which may be substituted by oneor more alkyl groups, and Y represents oxygen or sulphur. For example,the bivalent group of the formula —Y-A—O— represents —O—CH₂—CH₂—O— or—O—CH₂—CH₂—CH₂—O—.

Preferred are compounds of the formula I wherein R¹ and R² areindependently of each other an aliphatic, cycloaliphatic,cycloaliphatic-aliphatic, aromatic, aromatic-aliphatic, heteroaromaticor heteroaromatic-aliphatic group having up to 25 carbon atoms, R³ andR⁴ are independently of each other a group of one of the formulae XI toXIX,

wherein R²² to R²⁶ and R²⁹ to R⁵⁸ represent independently of each otherhydrogen, an aliphatic hydrocarbon group having up to 25 carbon atoms,or a group of the formula (III)

wherein R represents an aliphatic hydrocarbon group having up to 12carbon atoms, or two groups R²² to R²⁶ and R²⁹ to R⁵⁷ which are in theneighborhood of each other, together represent alkylene or alkenylenehaving up to 8 carbon atoms, thereby forming a ring, and R²⁷ and R²⁸ areindependently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, or a group of the formula (III)shown above, wherein R represents an aliphatic hydrocarbon group havingup to 12 carbon atoms, or R²⁷ and R²⁸ together or R²⁷ and R⁵⁸ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms, and the remaining substituents have the meanings givenabove.

Especially preferred are compounds of the formula I wherein R¹ and R²are independently of each other an aliphatic, cycloaliphatic orcycloaliphatic-aliphatic hydrocarbon group having up to 25 carbon atoms,

a and d represent 0,b, c, e, and f represent 1,Ar², Ar³, Ar⁵, and Ar⁶ are independently of each other a bivalent groupof the formula IV,

wherein R⁶ and R⁷ are independently of each other hydrogen orC₁-C₂₅alkyl, andR³ and R⁴ are independently of each other a group of the formula

wherein R⁵⁸ represents hydrogen or an aliphatic hydrocarbon group havingup to 25 carbon atoms, andR²⁷ and R²⁸ are independently of each other hydrogen or C₁-C₂₅alkyl.

More especially preferred are compounds of the formula I wherein R¹ andR² are independently of each other an aliphatic, cycloaliphatic orcycloaliphatic-aliphatic hydrocarbon group having up to 25 carbon atoms,

a and d represent 0,b, c, e, and f represent 1,Ar² and Ar⁵ are independently of each other a bivalent group of theformula IV,

wherein one of R⁶ and R⁷ represents C₁-C₂₅alkyl while the other of R⁶and R⁷ represents hydrogen or C₁-C₂₅alkyl,Ar³ and Ar⁶ are a bivalent group of the formula IV, wherein each of R⁶and R⁷ represents hydrogen, andR³ and R⁴ are independently of each other a group of the formula

wherein R⁵⁸ represents hydrogen or an aliphatic hydrocarbon group havingup to 25 carbon atoms, andone of R²⁷ and R²⁸ represents C₁-C₂₅alkyl while the other of R²⁷ and R²⁸represents hydrogen or C₁-C₂₅alkyl.

Very preferred are compounds of the formula I wherein

R¹ and R² are independently of each other an alkyl group having up to 49carbon atoms,a and d are independently of each other 0, 1 or 2,Ar¹ and Ar⁴ are independently of each other a bivalent group of theformula IV

whereinR⁶ and R⁷ are independently of each other hydrogen or C₁-C₂₅alkyl,b, c, e, and f independently of each other represent 1, 2 or 3Ar², Ar³, Ar⁵, and Ar⁶ are independently of each other a bivalent groupof the formula IV,

wherein R⁶ and R⁷ are independently of each other hydrogen, C₁-C₂₅alkyl,or C₇-C₂₅aralkyl, andR³ and R⁴ are independently of each other a group of one of the formulaeXI to XIII, XV, XVI and XIX

wherein R²² to R²⁶, R²⁹ to R³³, R⁴¹ to R⁵⁵, R⁵⁷ and R⁵⁸ representindependently of each other hydrogen, an aliphatic hydrocarbon grouphaving up to 25 carbon atoms, aryl, alkoxy having up to 18 carbon atoms,or halogen, or two groups R²² to R²⁶ which are in the neighborhood ofeach other, together represent alkylene or alkenylene having up to 8carbon atoms, thereby forming a ring, andR²⁷ and R²⁸ are independently of each other hydrogen, C₁-C₂₅alkyl, orC₇-C₂₅aralkyl, or R²⁷ and R²⁸ together represent alkylene or alkenylenewhich may be both bonded via oxygen and/or sulfur to the thienyl residueand which may both have up to 25 carbon atoms.

Very preferred are especially the above-mentioned compounds of theformula I wherein R¹ and R² have the same meaning and the side chains ofthe formulae XLV and XLVI are identical to each other.

Most preferred are the compounds of the formula I described in theExamples, especially a compound of the general formula I selected fromthe compounds having the formulae 13, 22, 23, 24, 25, 26, 32, 38, 44,45, 50, 55, 56, 58, 59, 60, 61, 63, 64, 70, 74, 76, 78, 80, 81, 82, 83,84, 85, 86, 87, 88 and 89, respectively, which are depicted in theExamples.

The compounds of the formula I can be manufactured by known methods.

A possible route of manufacture starts from a compound of the formulaXXXIV

wherein a and d represent 1 and Ar¹ and Ar⁴ have the meanings givenabove, or from a compound of the formula XXXV

wherein a and d represent 0, b and e represent 1, and Ar² and Ar⁵ havethe meanings given above.

Said starting compounds of the formulae XXXIV and XXXV can be obtainedas described in U.S. Pat. No. 4,579,949 by reacting (in the presence ofa strong base) one mole of a disuccinate, like dimethyl succinate, with1 mole of a nitrile of the formulae XXXVI or XXXVII

H—Ar¹—CN (XXXVI) H—Ar⁴—CN (XXXVII)

and 1 mole of a nitrile of the formulae XXXVIII or XXXIX.

H—Ar²—CN (XXXVIII) H—Ar⁵—CN (XXXIX)

Alternatively, said starting compounds of the formulae XXXIV and XXXVcan be obtained as described in U.S. Pat. No. 4,659,775 by reacting anitrile with a suitable ester, like a pyrrolinon-3-carboxylic esterderivative.

The thus obtained compound of the formula XXXIV or the thus obtainedcompound of the formula XXXV is then N-alkylated for introduction of thegroups R¹ and R², e.g. by reaction with a bromide of the formula R¹—Bror R²—Br in the presence of a suitable base, like potassium carbonate,in a suitable solvent, like N-methyl-pyrrolidone. The reaction iscarried out at a temperature from about room temperature to about 180°C., preferably from about 100° C. to about 170° C., e.g. at 140° C.

The thus obtained compound of the formula XL

wherein a and d represent 1, and R¹, R², Ar¹ and Ar⁴ have the meaningsgiven above, or the thus obtained compound of the formula XLI

wherein a and d represent 0, b and e represent 1, and R¹, R², Ar² andAr⁵ have the meanings given above, is then reacted with a suitablebrominating agent, like N-bromo-succinimide, to yield a compound of theformulae XLII and XLIII, respectively.

The bromination is carried out in a suitable solvent, like chloroform,using two equivalents of N-bromo-succinimide at a temperature between−30° C. and +50° C., preferably between −10° C. and room temperature,e.g. at 0° C.

The compounds of the formulae XLII or XLIII can then be“side-chain-elongated”, by step-wise adding further groups Ar¹—H, Ar⁴—H,Ar²—H, Ar⁵—H, Ar³—R³, and Ar⁶—R⁴. The step-wise addition of these groupscan be effected e.g. by reacting a compound of the formulae XLII orXLIII with a suitable tin compound of the formula XLIV

(R⁵⁹)₃Sn—Ar^(1-6 (XLIV))

wherein R⁵⁹ represents C₁₋₇alkyl, like butyl, and Ar¹⁻⁶ representsAr¹—H, Ar⁴—H, Ar²—H, Ar⁵—H, Ar³—R³, or Ar⁶—R⁴, respectively.

The reaction is carried out in the presence of a suitable palladiumcatalyst, like Pd(P[C₆H₅]₃)₄, in a suitable solvent, e.g. an aromatichydrocarbon solvent, like toluene, at a temperature between about 50° C.and 180° C., e.g. under reflux, and under inert conditions including,inter alia, the use of dry solvents. After cooling down, the reactionmixture may be e.g. filtrated, e.g. on a double layer silica gel/Hyflo®,concentrated and the desired compound precipitated, e.g. by addition ofmethanol.

The “side-chain-elongation” of the compounds of the formulae XLII orXLIII with an additional thienyl residue can also be effected e.g. byreaction with a mixture of 2-thienylboronic acid pinacol ester,Pd₂(dba)₃ [tris(dibenzylideneacetone)-di-palladium)] andtri-tert-butyl-phosphonium-tetrafluoroborate in tetrahydrofurane.

The 2-thienylboronic acid pinacol ester may be obtained e.g. by addingsubstituted or unsubstituted thiophene to a mixture prepared fromn-butyl-lithium and diisopropylamine and by adding2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane to the thusobtained mixture.

Analogously, the “side-chain-elongation” of the compounds of theformulae XLII or XLIII with an additional phenyl or biphenyl residue maybe effected with phenyl-boronic acid pinacol ester or biphenyl-boronicacid pinacol ester.

Alternatively, for the manufacture of compounds of the formula I whereinthe side chains of the formulae XLV and XLVI

are identical to each other, it is also possible to build up thecomplete side chains first and then reacting a nitrile of the formulaXLVII

with a suitable disuccinate, e.g. di-tert-amyl succinate. For example, amixture of iron(III)-chloride (FeCl₃), sodium, and tert-amylalcohol maybe heated to 60-160° C., e.g. 110° C., before a mixture of the nitrileof the formula XLVII and di-tert-amyl succinate is added drop wise.After stirring the reaction mixture until the reaction is complete, e.g.for about 19 hours at 110° C., the reaction mixture is poured onto awater-methanol mixture.

Compounds of the formulae XLVa and XLVIa containing the complete sidechains can be

manufactured e.g. by reacting a bromo derivative of the formula Br—Ar¹etc. first with magnesium in diethyl ether and then adding the thusobtained Grignard solution to a solution in diethyl ether of Ni(dppp)Cl₂and a mono- or, if desired, dibromo compound of the formula Br—Ar² orBr—Ar²T-Br, respectively.

The conversion of a compound of the formula XLVIa into the nitrile ofthe formula XLVII may be effected e.g. by adding a solution of acompound of the formula XLVIa, e.g. in toluene, to the reaction mixtureobtained by adding triflic anhydride to a solution ofN-formylmethylaniline in e.g. toluene, and reacting the obtainedaldehyde of the formula XLVIIa

with hydroxylamine sulfate in e.g. dimethyl formamide.

The thus obtained compound of the formula I wherein R¹ and R² arehydrogen may then be transformed into a desired end product of theformula I wherein R¹ and R² are e.g. an aliphatic, cycloaliphatic,cycloaliphatic-aliphatic, or aromatic-aliphatic group, like especiallysuch an hydrocarbon group, by N-alkylation, e.g. analogously asdescribed above, or by heating a solution thereof and potassiumcarbonate in dimethyl formamide followed by addition of R¹—Br or R²—Br,or by reaction with a suitable iodide of the formula R¹—I or R²—I. Forexample, a mixture of a compound of the formula I wherein R¹ and R² arehydrogen in N-methyl-pyrrolidone is treated, preferably under cooling,e.g. to a temperature between about 0° C. and 10° C., e.g. about 5° C.,with a suitable strong base, e.g. a suitable hydride, like an alkalimetal hydride, e.g. sodium hydride. Thereafter, the iodide of theformula R¹—I or R²—I is added.

The nitrile of the formula XLVII used as starting material may beprepared e.g. from the corresponding aldehyde of the formula XLVIII,

e.g. by reaction with hydroxylamine.

Said aldehyde of the formula XLVIII may be prepared e.g. from a compoundof the formula IL,

e.g. by adding a solution of a compound of the formula IL in a suitablesolvent, like toluene, to the reaction mixture of N-formylmethylanilinein a suitable solvent, like toluene, and triflic anhydride.

The present invention relates also to new starting materials, especiallyto compounds of the formula I wherein one or both of R¹ and R² arehydrogen, preferably to such compounds which, like the end products ofthe formula I can also be used as the semiconductor layer insemiconductor devices. Preferred are those starting materials of theformula I wherein one or both of R¹ and R² are hydrogen and whichcontain at least two or three Ar groups in each side chain.

The compounds of the formula I show clear p-type transistor behavior andcan be used as the semiconductor layer in semiconductor devices.Accordingly, the present invention also relates to a semiconductordevice comprising as a semiconducting effective means a compound of theformula I

wherein R¹ and R² are independently of each other an aliphatic grouphaving 7 to 25 carbon atoms, or a cycloaliphatic,cycloaliphatic-aliphatic, aromatic, aromatic aliphatic, heteroaromaticor heteroaromatic-aliphatic group having up to 25 carbon atoms,a and d independently of each other are 0, 1, 2 or 3,Ar¹ and Ar⁴ are independently of each other a bivalent group of theformula II or IV

whereinR⁶ and R⁷ are as defined below,p represents 0, 1, or 2,R⁵ is an aliphatic hydrocarbon group having up to 25 carbon atoms, ortwo vicinal groups R⁵ together represent alkylene or alkenylene havingup to 7 carbon atoms, it being possible that two groups R⁵ present inthe group of formula II differ from each other,b and e independently of each other represent 1, 2 or 3,c and f independently of each other represent 0, 1, 2 or 3,Ar², Ar³, Ar⁵, and Ar⁶ are independently of each other a bivalent groupof one of the formulae IV to X and L,

wherein R⁶, R⁷, R⁸, R⁹, R¹², R¹³, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹are independently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, or heteroaryl, or R⁶ and R⁷ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms,R¹⁰ and R¹¹ are independently of each other hydrogen, C₁-C₁₈alkyl,C₆-C₂₄aryl, heteroaryl, or R¹⁰ and R¹¹ together represent oxo or form afive or six membered ring, which is unsubstituted or substituted bya) an aliphatic hydrocarbon group having up to 18 carbon atoms,b) C₁-C₁₈alkoxy or C₂-C₁₈alkylenedioxy in both of which carbon atomswhich are not adjacent to oxygen may be replaced by oxygen, orc) C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, C₃-C₁₂cycloalkyl orC₄-C₁₂cycloalkyl-alkyl, andR³ and R⁴ are independently of each other a group of one of the formulaeXI to XIX,

wherein R²² to R²⁶ and R²⁹ to R⁵⁸ represent independently of each otherhydrogen, an aliphatic hydrocarbon group having up to 25 carbon atoms,or a group of the formula (III)

wherein R represents an aliphatic hydrocarbon group having up to 12carbon atoms, or two groups R²² to R²⁶ and R²⁹ to R⁵⁷ which are in theneighborhood of each other, together represent alkylene or alkenylenehaving up to 8 carbon atoms, thereby forming a ring, and R²⁷ and R²⁸ areindependently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, or a group of the formula (III)shown above, wherein R represents an aliphatic hydrocarbon group havingup to 12 carbon atoms, or R²⁷ and R²⁸ together or R²⁷ and R⁵⁸ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms, especially to a semiconductor device comprising as asemiconducting effective means a compound of the formula I as defined inthis paragraph with the proviso that at least one of R⁶, R⁷, R²⁷, R²⁸and R⁵⁸ is different from hydrogen.

The invention relates especially to a semiconductor device comprising asa semiconducting effective means a compound of the formula I describedin the Examples selected from the compounds having the formulae 3, 16,53, 67, 68, 69, 71, and 77, respectively, which are depicted in theExamples.

Preferably, the invention relates to a semiconductor device comprisingas a semiconducting effective means a compound of the general formula Iselected from the compounds having the formulae 13, 22, 23, 24, 25, 26,32, 38, 44, 45, 50, 55, 56, 58, 59, 60, 61, 63, 64, 70, 74, 76, 78, 80,81, 82, 83, 84, 85, 86, 87, 88, and 89, respectively, which are depictedin the Examples.

Preferably said semiconductor device is a diode, a photodiode, a sensor,an organic field effect transistor (OFET), a transistor for flexibledisplays, or a solar cell, or a device containing a diode and/or anorganic field effect transistor, and/or a solar cell. There are numeroustypes of semiconductor devices. Common to all is the presence of one ormore semiconductor materials. Semiconductor devices have been described,for example, by S. M. Sze in Physics of Semiconductor Devices, 2^(nd)edition, John Wiley and Sons, New York (1981). Such devices includerectifiers, transistors (of which there are many types, including p-n-p,n-p-n, and thin-film transistors), light emitting semiconductor devices(for example, organic light emitting diodes in display applications orbacklight in e.g. liquid crystal displays), photoconductors, currentlimiters, solar cells, thermistors, p-n junctions, field-effect diodes,Schottky diodes, and so forth. In each semiconductor device, thesemiconductor material is combined with one or more metals and/orinsulators to form the device. Semiconductor devices can be prepared ormanufactured by known methods such as, for example, those described byPeter Van Zant in Microchip Fabrication, Fourth Edition, McGraw-Hill,New York (2000). In particular, organic electronic components can bemanufactured as described by D. R. Gamota et al. in Printed Organic andMolecular Electronics, Kluver Academic Publ., Boston, 2004.

A particularly useful type of transistor device, the thin-filmtransistor (TFT), generally includes a gate electrode, a gate dielectricon the gate electrode, a source electrode and a drain electrode adjacentto the gate dielectric, and a semiconductor layer adjacent to the gatedielectric and adjacent to the source and drain electrodes (see, forexample, S. M. Sze, Physics of Semiconductor Devices, 2.sup.nd edition,John Wiley and Sons, page 492, New York (1981)). These components can beassembled in a variety of configurations. More specifically, an organicthin-film transistor (OTFT) has an organic semiconductor layer.

Typically, a substrate supports the OTFT during manufacturing, testing,and/or use. Optionally, the substrate can provide an electrical functionfor the OTFT. Useful substrate materials include organic and inorganicmaterials. For example, the substrate can comprise silicon materialsinclusive of various appropriate forms of silicon, inorganic glasses,ceramic foils, polymeric materials (for example, acrylics, polyester,epoxies, polyamides, polycarbonates, polyimides, polyketones,poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene)(sometimes referred to as poly(ether ether ketone) or PEEK),polynorbornenes, polyphenyleneoxides, poly(ethylenenaphthalenedicarboxylate) (PEN), poly(ethylene terephthalate) (PET),poly(phenylene sulfide) (PPS)), filled polymeric materials (for example,fiber-reinforced plastics (FRP)), and coated metallic foils.

The gate electrode can be any useful conductive material. For example,the gate electrode can comprise doped silicon, or a metal, such asaluminum, chromium, gold, silver, nickel, palladium, platinum, tantalum,and titanium. Conductive oxides, such as indium tin oxide (ITO), orconducting inks/pastes comprised of carbon black/graphite or colloidalsilver dispersions, optionally containing polymer binders can also beused. Conductive polymers also can be used, for example polyaniline orpoly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS). Inaddition, alloys, combinations, and multilayers of these materials canbe useful. In some OTFTs, the same material can provide the gateelectrode function and also provide the support function of thesubstrate. For example, doped silicon can function as the gate electrodeand support the OTFT.

The gate dielectric is generally provided on the gate electrode. Thisgate dielectric electrically insulates the gate electrode from thebalance of the OTFT device. Useful materials for the gate dielectric cancomprise, for example, an inorganic electrically insulating material.

The gate dielectric (insulator) can be a material, such as, an oxide,nitride, or it can be a material selected from the family offerroelectric insulators (e.g. organic materials such as poly(vinylidenefluoride/trifluoroethylene or poly(m-xylylene adipamide)), or it can bean organic polymeric insulator (e.g. poly(methacrylate)s,poly(acrylate)s, polyimides, benzocyclobutenes (BCBs), parylenes,polyvinylalcohol, polyvinylphenol (PVP), polystyrenes, polyester,polycarbonates) as for example described in J. Veres et al. Chem. Mat.2004, 16, 4543 or A. Facchetti et al. Adv. Mat. 2005, 17, 1705. Specificexamples of materials useful for the gate dielectric includestrontiates, tantalates, titanates, zirconates, aluminum oxides, siliconoxides, tantalum oxides, titanium oxides, silicon nitrides, bariumtitanate, barium strontium titanate, barium zirconate titanate, zincselenide, and zinc sulphide, including but not limited toPbZr_(x)Ti_(1-x)O₃ (PZT), Bi₄Ti₃O₁₂, BaMgF₄, Ba(Zr_(1-x)Ti_(x))O₃ (BZT).In addition, alloys, hybride materials (e.g. polysiloxanes ornanoparticle-filled polymers) combinations, and multilayers of thesematerials can be used for the gate dielectric. The thickness of thedielectric layer is, for example, from about 10 to 1000 nm, with a morespecific thickness being about 100 to 500 nm, providing a capacitance inthe range of 0.1-100 nanofarads (nF).

The source electrode and drain electrode are separated from the gateelectrode by the gate dielectric, while the organic semiconductor layercan be over or under the source electrode and drain electrode. Thesource and drain electrodes can be any useful conductive materialfavourably providing a low resistance ohmic contact to the semiconductorlayer. Useful materials include most of those materials described abovefor the gate electrode, for example, aluminum, barium, calcium,chromium, gold, silver, nickel, palladium, platinum, titanium,polyaniline, PEDOT:PSS, other conducting polymers, alloys thereof,combinations thereof, and multilayers thereof. Some of these materialsare appropriate for use with n-type semiconductor materials and othersare appropriate for use with p-type semiconductor materials, as is knownin the art.

The thin film electrodes (that is, the gate electrode, the sourceelectrode, and the drain electrode) can be provided by any useful meanssuch as physical vapor deposition (for example, thermal evaporation orsputtering) or (ink jet) printing methods. The patterning of theseelectrodes can be accomplished by known methods such as shadow masking,additive photolithography, subtractive photolithography, printing,microcontact printing, and pattern coating.

The present invention further provides a thin film transistor devicecomprising

a plurality of electrically conducting gate electrodes disposed on asubstrate;a gate insulator layer disposed on said electrically conducting gateelectrodes;a plurality of sets of electrically conductive source and drainelectrodes disposed on said insulator layer such that each of said setsis in alignment with each of said gate electrodes;an organic semiconductor layer disposed in the channel between sourceand drain electrodes on said insulator layer substantially overlappingsaid gate electrodes; wherein said organic semiconductor layer comprisea compound of the formula I.

The present invention further provides a process for preparing a thinfilm transistor device comprising the steps of:

depositing a plurality of electrically conducting gate electrodes on asubstrate;depositing a gate insulator layer on said electrically conducting gateelectrodes;depositing a plurality of sets of electrically conductive source anddrain electrodes on said layer such that each of said sets is inalignment with each of said gate electrodes;depositing a layer comprising a compound of the formula I on saidinsulator layer such that said layer comprising the compound of formulaI substantially overlaps said gate electrodes, thereby producing thethin film transistor device.

The above-mentioned layer comprising a compound of formula I mayadditionally comprise at least another material. The other material canbe, but is not restricted to another compound of the formula I, asemi-conducting polymer, a polymeric binder, organic small moleculesdifferent from a compound of the formula I, carbon nanotubes, afullerene derivative, inorganic particles (quantum dots, quantum rods,quantum tripods, TiO₂, ZnO etc.), conductive particles (Au, Ag etc.),and insulator materials like the ones described for the gate dielectric(PET, PS etc.). As stated above, the semiconductive layer can also becomposed of a mixture of one or more small molecules of the formula Iand a polymeric binder. The ratio of the small molecules of formula I tothe polymeric binder can vary from 5 to 95 percent. Preferably, thepolymeric binder is a semicrystalline polymer such as polystyrene (PS),high-density polyethylene (HDPE), polypropylene (PP) andpolymethylmethacrylate (PMMA). With this technique, a degradation of theelectrical performance can be avoided (cf. WO 2008/001123 A1).

For heterojunction solar cells (bulk heterojunction solar cells) theactive layer comprises preferably a mixture of a compound of the formulaI and a fullerene, such as [60]PCBM (=6,6-phenyl-C₆₁-butyric acid methylester), or [70]PCBM, in a weight ratio of 1:1 to 1:3. MethanofullerenePhenyl-C₆₁-Butyric-Acid-Methyl-Ester ([60]PCBM), i.e.1-[3-(methoxy-carbonyl)propyl]-1-phenyl-[6.6]C₆₁-3′H-cyclopropa[1,9][5,6]fullerene-C₆₀-1h-3′-butanoicacid 3′-phenyl methyl ester, is an effective solution processable n-typeorganic semiconductor. It is blended with conjugated polymers withnano-particles such as C₆₀.

Any suitable substrate can be used to prepare the thin films of thecompounds of the formula I. Preferably, the substrate used to preparethe above thin films is a metal, silicon, plastic, paper, coated paper,fabric, glass or coated glass.

Alternatively, a TFT is fabricated, for example, by solution depositionof a compound of the formula I on a highly doped silicon substratecovered with a thermally grown oxide layer followed by vacuum depositionand patterning of source and drain electrodes.

In yet another approach, a TFT is fabricated by deposition of source anddrain electrodes on a highly doped silicon substrate covered with athermally grown oxide and then solution deposition of the compound ofthe formula Ito form a thin film.

The gate electrode could also be a patterned metal gate electrode on asubstrate or a conducting material such as a conducting polymer, whichis then coated with an insulator applied either by solution coating orby vacuum deposition on the patterned gate electrodes.

Any suitable solvent can be used to dissolve, and/or disperse a compoundof the formula I, provided it is inert and can be removed partly, orcompletely from the substrate by conventional drying means (e.g.application of heat, reduced pressure, airflow etc.). Suitable organicsolvents for processing the semiconductors of the invention include, butare not limited to, aromatic or aliphatic hydrocarbons, halogenated suchas chlorinated or fluorinated hydrocarbons, esters, ethers amides, suchas chloroform, tetrachloroethane, tetrahydrofuran, toluene, tetraline,anisole, xylene, ethyl acetate, methyl ethyl ketone, dimethyl formamide,dichlorobenzene, trichlorobenzene, propylene glycol monomethyl etheracetate (PGMEA) and mixtures thereof. The solution, and/or dispersion isthen applied by a method, such as, spin-coating, dip-coating, screenprinting, microcontact printing, doctor blading or other solutionapplication techniques known in the art on the substrate to obtain thinfilms of the semiconducting material.

The term “dispersion” covers any composition comprising a compound ofthe formula I, which is not fully dissolved in a solvent. The dispersioncan be done selecting a composition including at least a compound offormula I, or a mixture containing a compound of formula I, and asolvent, wherein the polymer exhibits lower solubility in the solvent atroom temperature but exhibits greater solubility in the solvent at anelevated temperature, wherein the composition gels when the elevatedtemperature is lowered to a first lower temperature without agitation;

-   -   dissolving at the elevated temperature at least a portion of the        compound of the formula I in the solvent; lowering the        temperature of the composition from the elevated temperature to        the first lower temperature; agitating the composition to        disrupt any gelling, wherein the agitating commences at any time        prior to, simultaneous with, or subsequent to the lowering the        elevated temperature of the composition to the first lower        temperature; depositing a layer of the composition wherein the        composition is at a second lower temperature lower than the        elevated temperature; and drying at least partially the layer.

The dispersion can also be constituted of (a) a continuous phasecomprising a solvent, a binder resin, and optionally a dispersing agent,and (b) a disperse phase comprising a compound of formula I, or amixture containing a compound of formula I of the present invention. Thedegree of solubility of the compound of formula I in the solvent mayvary for example from 0.5% to about 20% solubility, particularly from 1%to about 5% solubility.

Preferably, the thickness of the organic semiconductor layer is in therange of from about 5 to about 1000 nm, especially the thickness is inthe range of from about 10 to about 100 nm.

The compounds of the formula I can be used alone or in combination asthe organic semiconductor layer of the semiconductor device. The layercan be provided by any useful means, such as, for example, vapordeposition and printing techniques. The compounds of the formula I whichare sufficiently soluble in organic solvents can be solution depositedand patterned (for example, by spin coating, dip coating, ink jetprinting, gravure printing, flexo printing, offset printing, screenprinting, microcontact (wave)-printing, drop or zone casting, or otherknown techniques).

The compounds of the formula I can be used in integrated circuitscomprising a plurality of OTFTs, as well as in various electronicarticles. Such articles include, for example, radio-frequencyidentification (RFID) tags, backplanes for flexible displays (for usein, for example, personal computers, cell phones, or handheld devices),smart cards, memory devices, sensors (e.g. light-, image-, bio-, chemo-,mechanical- or temperature sensors), especially photodiodes, or securitydevices and the like. Due to its ambi-polarity the material can also beused in Organic Light Emitting Transistors (OLET).

The invention provides organic photovoltaic (PV) devices (solar cells)comprising a compound of the formula I.

The PV device comprise in this order:

(a) a cathode (electrode),(b) optionally a transition layer, such as an alkali halogenide,especially lithium fluoride,(c) a photoactive layer,(d) optionally a smoothing layer,(e) an anode (electrode),(f) a substrate.

The photoactive layer comprises the compounds of the formula I.Preferably, the photoactive layer is made of a compound of the formulaI, as an electron donor and an acceptor material, like a fullerene,particularly a functionalized fullerene PCBM, as an electron acceptor.As stated above, the photoactive layer may also contain a polymericbinder. The ratio of the small molecules of formula I to the polymericbinder can vary from 5 to 95 percent. Preferably, the polymeric binderis a semicrystalline polymer such as polystyrene (PS), high-densitypolyethylene (HDPE), polypropylene (PP) and polymethylmethacrylate(PMMA).

The fullerenes useful in this invention may have a broad range of sizes(number of carbon atoms per molecule). The term fullerene as used hereinincludes various cage-like molecules of pure carbon, includingBuckminsterfullerene (C₆₀) and the related “spherical” fullerenes aswell as carbon nanotubes. Fullerenes may be selected from those known inthe art ranging from, for example, C₂₀C₁₀₀₀. Preferably, the fullereneis selected from the range of C₆₀ to C₉₆. Most preferably the fullereneis C₆₀ or C₇₀, such as [60]PCBM, or [70]PCBM. It is also permissible toutilize chemically modified fullerenes, provided that the modifiedfullerene retains acceptor-type and electron mobility characteristics.The acceptor material can also be a material selected from the groupconsisting of another polymer of formula I or any semi-conductingpolymer provided that the polymers retain acceptor-type and electronmobility characteristics, organic small molecules, carbon nanotubes,inorganic particles (quantum dots, quantum rods, quantum tripods, TiO₂,ZnO etc.).

The electrodes are preferably composed of metals or “metal substitutes”.Herein the term “metal” is used to embrace both materials composed of anelementally pure metal, e.g., Mg, and also metal alloys which arematerials composed of two or more elementally pure metals, e.g., Mg andAg together, denoted Mg:Ag. Here, the term “metal substitute” refers toa material that is not a metal within the normal definition, but whichhas the metal-like properties that are desired in certain appropriateapplications. Commonly used metal substitutes for electrodes and chargetransfer layers would include doped wide-bandgap semiconductors, forexample, transparent conducting oxides such as indium tin oxide (ITO),gallium indium tin oxide (GITO), and zinc indium tin oxide (ZITO).Another suitable metal substitute is the transparent conductive polymerpolyanaline (PANI) and its chemical relatives, or PEDOT:PSS. Metalsubstitutes may be further selected from a wide range of non-metallicmaterials, wherein the term “non-metallic” is meant to embrace a widerange of materials provided that the material is free of metal in itschemically uncombined form. Highly transparent, non-metallic, lowresistance cathodes or highly efficient, low resistancemetallic/non-metallic compound cathodes are, for example, disclosed inU.S. Pat. No. 6,420,031 and U.S. Pat. No. 5,703,436.

The substrate can be, for example, a plastic (flexible substrate), orglass substrate.

In another preferred embodiment of the invention, a smoothing layer issituated between the anode and the photoactive layer. A preferredmaterial for this smoothing layer comprises a film of3,4-polyethylenedioxythiophene (PEDOT), or3,4-polyethylenedioxythiophene:polystyrene-sulfonate (PEDOT:PSS).

In a preferred embodiment of the present invention, the photovoltaiccell comprises, as described for example, in U.S. Pat. No. 6,933,436 atransparent glass carrier, onto which an electrode layer made ofindium/tin oxide (ITO) is applied. This electrode layer generally has acomparatively rough surface structure, so that it is covered with asmoothing layer made of a polymer, typically PEDOT, which is madeelectrically conductive through doping. The photoactive layer is made oftwo components, has a layer thickness of, for example, 100 nm to a fewμm depending on the application method, and is applied onto thissmoothing layer. The photoactive layer is made of a compound of theformula I, as an electron donor and a fullerene, particularlyfunctionalized fullerene PCBM, as an electron acceptor. These twocomponents are mixed with a solvent and applied as a solution onto thesmoothing layer by, for example, the spin-coating method, the dropcasting method, the Langmuir-Blodgett (“LB”) method, the ink jetprinting method and the dripping method. A squeegee or printing methodcould also be used to coat larger surfaces with such a photoactivelayer. Instead of toluene, which is typical, a dispersion agent such aschlorobenzene is preferably used as a solvent. Among these methods, thevacuum deposition method, the spin-coating method, the ink jet printingmethod and the casting method are particularly preferred in view of easeof operation and cost.

In the case of forming the layer by using the spin-coating method, thecasting method and ink jet printing method, the coating can be carriedout using a solution and/or dispersion prepared by dissolving, ordispersing the composition in a concentration of from 0.01 to 90% byweight in an appropriate organic solvent such as benzene, toluene,xylene, tetrahydrofurane, methyltetrahydrofurane, N,N-dimethylformamide,acetone, acetonitrile, anisole, dichloromethane, dimethylsulfoxide,chlorobenzene, 1,2-dichlorobenzene and mixtures thereof.

Before a counter electrode is applied, a thin transition layer, whichmust be electrically insulating, having a layer thickness of, forexample, 0.6 nm, is applied to the photoactive layer. In this exemplaryembodiment, this transition layer is made of an alkali halogenide,namely a lithium fluoride, which is vapor deposited in a vacuum of2·10⁻⁶ torr at a rate of 0.2 nm/minute.

If ITO is used as a hole-collecting electrode, aluminum, which is vapordeposited onto the electrically insulating transition layer, is used asan electron-collecting electrode. The electric insulation properties ofthe transition layer obviously prevent influences which hinder thecrossing of the charge carrier from being effective, particularly in thetransition region from the photoactive layer to the transition layer.

In a further embodiment of the invention, one or more of the layers maybe treated with plasma prior to depositing the next layer. It isparticularly advantageous that prior to the deposition of the PEDOT:PSSlayer the anode material is subjected to a mild plasma treatment.

As an alternative to PEDOT:PSS a crosslinkable hole-transport materialbased on triarylamines as referenced in Macromol. Rapid Commun. 20,224-228 (1999) can be used. In addition to the triarylamine material thelayer can also include an electron acceptor to improve electrontransport. Such compounds are disclosed in US 2004/0004433. Preferably,the electron acceptor material is soluble in one or more organicsolvents. Typically, the electron acceptor material is present in therange of 0.5 to 20% by weight of the triarylamine material.

The photovoltaic (PV) device can also consist of multiple junction solarcells that are processed on top of each other in order to absorb more ofthe solar spectrum. Such structures are, for example, described in App.Phys. Let. 90, 143512 (2007), Adv. Funct. Mater. 16, 1897-1903 (2006)and WO2004/112161.

A so called ‘tandem solar cell’ comprise in this order:

(a) a cathode (electrode),(b) optionally a transition layer, such as an alkali halogenide,especially lithium fluoride,(c) a photoactive layer,(d) optionally a smoothing layer,(e) a middle electrode (such as Au, Al, ZnO, TiO₂ etc.)(f) optionally an extra electrode to match the energy level,(g) optionally a transition layer, such as an alkali halogenide,especially lithium fluoride,(h) a photoactive layer,(i) optionally a smoothing layer,(j) an anode (electrode),(k) a substrate.

The PV device can also be processed on a fiber as described, forexample, in US20070079867 and US 20060013549.

Due to their excellent self-organising properties the materials or filmscomprising the compounds of the formula I can also be used alone ortogether with other materials in or as alignment layers in LCD or OLEDdevices, as described for example in US200310021913.

The following examples illustrate the invention.

Abbreviations:

m.p. melting pointIn the reported NMR spectra the following abbreviations are used:d: dubletdd: dublet of dubletm: multiplets: singulett: tripletquint: quintetsext: sextet

EXAMPLE 1 Manufacture of the Semiconducting Compound of the Formula 3

a) A solution of 4.5 g of the 1,4-diketopyrrolo[3,4-c]pyrrole (DPP)derivative of the formula 1, 6.23 g of K₂CO₃ and 8.68 g of1-bromo-2-ethyl-hexyl in 60 ml of N-methyl-pyrrolidone (NMP) is heatedto 140° C. for 6 h. The mixture is washed with water and extracted withdichloromethane. The organic phase is then dried and filtered on adouble layer of silica gel and Hyflo® (CAS 91053-39-3; Fluka 56678)before it is concentrated. The residue is dissolved in 100 ml ofchloroform, cooled down to 0° C. and 2 equivalents of N-bromosuccinimideare then added portion wise over a period of 1 h. After the reaction hasbeen completed, the mixture is washed with water. The organic phase isextracted, dried and concentrated. The compound is then purified over asilica gel column to give 1.90 g of a violet powder of the DPPderivative of the formula 2.

b) A solution of 1.28 g of the dibrominated DPP derivative of theformula 2, 2.41 g of the tin derivative depicted above, and 215 mg ofPd(PPh₃)₄ in 30 ml of dry toluene is refluxed overnight under inertconditions. After cooling down, the mixture is filtrated on a doublelayer silica gel/Hyflo®, concentrated and precipitated with methanol.The precipitate is filtrated and rinsed with methanol to give 1.17 g ofa blue solid of the DPP derivative of the formula 3.

EXAMPLE 2 Application of the Semiconducting Compound of the Formula 3

Bottom-gate thin film transistor (TFT) structures with p-Si gate (10 cm)are used for all experiments. A high-quality thermal SiO₂ layer of 300nm thickness served as gate-insulator of C_(i)=32.6 nF/cm² capacitanceper unit area. Source and drain electrodes are patterned byphotolithography directly on the gate-oxide. Gold source drainelectrodes defining channels of width W=10 mm and varying lengths L=4,8, 15, 30 m are used. Prior to deposition of the organic semiconductorthe SiO₂ surface is derivatized either with hexadimethylsilazane (HMDS)by exposing to a saturated silane vapour at 160° C. for 2 hours ortreating the substrate at 60° C. with a 0.1 m solution ofoctadecyltrichlorosilane (OTS) in toluene for 20 minutes. After rinsingwith iso-propanol the substrates are dried.

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 3 obtained in example 1 in a1% (w/w) solution in toluene. Before use the solution is filteredthrough 0.2 m filter. The spin coating is accomplished at a spinningspeed of 800 rpm (rounds per minute) for about 20 seconds in ambientconditions. The devices are dried at 80° C. for 1 hour beforeevaluation.

Transistor Performance

The transistor behaviour is measured on an automated transistor prober(TP-10, CSEM Zürich).

From a linear fit to the square root of the saturated transfercharacteristics a field effect mobility of 1×10⁻⁰³ cm²/Vs with an on/offcurrent ratio of 8.9×10⁵ can be determined. The threshold voltage is at−3.0 V.

Electrochemical Measurements According to Method A

Electrochemical data are obtained by cyclic voltammetry (PrincetonApplied Research-Versastat II) in solution. The experiments areperformed under argon in a saturated solution of anhydrous methylenechloride with 0.1 m tetrabutyl-ammonium hexafluorophosphate as thesupporting electrolyte. A silver Ag/AgCl couple is used aspseudoreference electrode. All data are referenced to theferrocene/ferrocenium redox couple, that is measured after the scan inthe same system. Ferrocene is bis(η⁵-cyclopentadienyl)iron. Ferroceniumis the oxidated form of ferrocene. The scan rate is 50 mV/s.

For each sample, the level is estimated using the formal potential(E_(1/2)) with the assumption that ferrocene, used as the internalstandard, has a HOMO (highest occupied molecular orbital) level of −4.8eV.

The resulting level HOMO level of example 1, i.e. of the compound of theformula 3, corresponds to a HOMO level of approx. −5.21 eV, respectivelya LUMO (lowest unoccupied molecular orbital) level of −3.31 eV.

Electrochemical Measurements According to Method B

For the example 2 and the following examples electrochemical data areobtained by cyclic voltammetry (Princeton Applied Research-Versastat II)following a slightly different method as described above for method A(inter alia, thin film instead of saturated solution). The experimentsare performed at room temperature under argon on drop-cast thin films inanhydrous acetonitrile with 0.1 m tetrabutyl-ammonium tetrafluoroborateas the supporting electrolyte. A silver Ag/AgCl couple was used aspseudoreference electrode. All data are referenced to theferrocene/ferrocenium redox couple, that is measured after the scan inthe same system. The scan rate is 100 mV/s (millivolt per second).

For each sample, the level is estimated using the formal potential(E_(1/2)) with the assumption that ferrocene, used as the internalstandard, has a HOMO level of −5.15 eV (electron volt). The resultinglevel of the DPP derivative of formula 3 corresponds to a HOMO level ofapprox. −5.5 eV, respectively a LUMO level of −3.8 eV.

In the perspective of using the compound of formula 3 blended with[60]PCBM in a solar cell device electrochemical data of [60]PCBM arealso obtained by cyclic voltammetry of a thin film. The resulting levelof [60]PCBM corresponds to a HOMO level of approx. −6.0 eV, respectivelya LUMO level of −4.3 eV.

EXAMPLE 3 Photovoltaic Application of the Semiconducting Compound ofFormula 3

A glass substrate (0.55 mm thickness) with patterned ITO (indium tinoxide) layer (65 nm thickness, Rs=15 Ohm) is used as basis formanufacturing the photovoltaic cell. A hole injection and smoothinglayer (PEDOT:PSS Baytron P, Bayer AG) is applied onto the patterned ITOlayer by spin coating at a rotating speed of 1500 rpm for 1 minute andthen accelerating up to 4000 rpm. 10 mg of the compound of the formula 3together with 10 mg of [60]PCBM fullerene are dissolved in 1 ml oftoluene, heated up to 50° C. and stirred for 3 hours and finally appliedonto the electron blocking layer by spin-coating at 500 rpm. Theso-formed active layer is then covered with a 1 nm thick LiF (lithiumfluoride) hole blocking layer and 100 nm Al (aluminium) electrode, bothapplied under vacuum in a vapour deposition equipment (Bestec, Germany).The actual area of active layer sandwiched between both ITO and Alelectrodes is about 9 mm².

The so-formed photovoltaic solar cell is exhibiting surprisingly goodperformance and efficiency when exposed to AM (Air Mass) 1.5 solarphoton flux (photon flux: number of photons per second per unit area).

EXAMPLE 4 Manufacture of the Semiconducting Compound of the Formula 13

a) To a solution of 40 g of 3-(2-ethylhexyl)thiophene of the formula 4and 0.4 ml of perchloric acid in 350 ml of chloroform at 12° C. areadded portion wise 36.2 g N-bromosuccinimide. At the end of the additionthe mixture is allowed to regain room temperature and is stirred for onehour. The reaction mixture is extracted with water, dried andconcentrated. The product is thereafter fractionated over a Vigreuxcolumn to yield 39.7 g of compound 5 as colorless liquid; ¹H-NMR data(ppm, CDCl₃): 7.11 1H d, 6.69 1H d, 2.43 2H d, 1.47-1.51 1H m, 1.15-1.238H m, 0.81 6H t.

b) Synthesis of Compound 7 Version 1 Via a Kumada Cross-CouplingReaction

In a reactor 0.28 g of freshly activated magnesium turnings aresuspended in 20 ml of diethyl ether and 2.7 g of the compound of theformula 5 are added carefully. The mixture is stirred for 2 hours atroom temperature and then refluxed overnight.

Into a second reactor 22 mg of Ni(dppp)Cl₂[dppp=propane-1,3-diylbis(diphenylphosphane)] and 1.0 g of2,5-dibromothiophene of the formula 6 are suspended in 20 ml of diethylether and cooled to 7° C. before the freshly prepared Grignard solutionof the compound of the formula 5 is added drop wise. The obtained darkmixture is stirred at room temperature over night. The reaction isquenched by the addition of 10% of hydrochloric acid (HCl). Aftercompletion the mixture is washed with water, dried and concentrated.Purification by distillation followed by column chromatography on silicagel affords 1.05 g of compound 7 as slightly yellow oil.

Version 2 Via a Suzuki Cross-Coupling Reaction

A mixture of 4.1 g of compound 5, 2.0 g of the diboronic ester of theformula 8, 6.9 g of potassium phosphate (K₃PO₄), 0.7 g of2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (S-Phos), 67 mg ofpalladium(II)acetate, 20 ml of dioxane, 20 ml of toluene and 12 ml ofwater is heated to 95° C. for 21 hours. The obtained mixture is dilutedwith diethyl ether and extracted with water, dried and concentrated.Purification is performed by bulb to bulb distillation followed bycolumn chromatography on silica gel and yields 1.9 g of compound 7 asslightly yellow oil; ¹H-NMR data (ppm, CDCl₃): 7.18 2H d, 7.04 2H s,6.91 2H d, 2.72 4H d, 1.63-1.67 2H m, 1.23-1.36 16H m, 0.81-0.86 12H m.

c) To a solution of 0.66 g of N-formylmethylaniline in 10 ml of tolueneare added at 5° C. 1.34 g of triflic anhydride, while a whiteprecipitate is formed. The reaction mixture is allowed to return to roomtemperature before 2.0 g of compound 7 are added, dissolved in 10 ml oftoluene. The mixture is heated to 110° C. for 22 hours. After cooling toroom temperature 5 ml of a 10% sodium hydroxide solution are added. Themixture is then extracted with water, dried and concentrated. Finalpurification is achieved by column chromatography on silica gel yielding1.58 g of compound 9 as yellow oil; ¹H-NMR data (ppm, CDCl₃): 9.84 1H s,7.56 1H s, 7.23 1H d, 7.22 1H d, 7.01 1H d, 6.92 1H s, 2.76 2H, d, 2.722H d, 1.61-1.71 2H m, 1.23-1.39 16H m, 0.81-0.89 12H m.

d) A mixture of 1.2 g of the aldehyde of the formula 9 and 0.2 g ofhydroxylamine hydrochloride in 10 ml of dimethyl formamide (DMF) isheated to 145° C. for 16 hours. After cooling to room temperature themixture is diluted with diethyl ether, washed with water, dried andconcentrated. The crude product is purified by filtration over a silicagel plug under reduced pressure affording 0.91 g of the desired nitrileof the formula 10 as dark oil.

¹H-NMR data (ppm, CDCl₃): 7.41 1H s, 7.22 1H d, 7.14 1H d, 7.08 1H d,6.92 1H s, 2.71 4H, d, 1.60-1.66 2H m, 1.17-1.35 16H m, 0.81-0.87 12H m.

e) A mixture of 5 mg iron trichloride (FeCl₃), 64 mg of sodium and 10 mlof t-Amylalcohol is heated to 110° C. for 20 minutes before a mixture of0.5 g of the nitrile of the formula 10 and 0.16 g of di-tert-amylsuccinate of the formula 11 is added drop wise. The reaction mixture isstirred at 110° C. for 19 hours before it is poured onto awater-methanol mixture. Büchner filtration and exhaustive washing withmethanol affords 340 mg of the desired 1,4-diketopyrrolo[3,4-c]pyrrole(DPP) derivative of the formula 12 as dark blue powder; ESI-MS m/z (%int.): 1077.5 ([M+H]+, 100%).

f) To a mixture of 0.25 g of the DPP derivative of the formula 12 in 10ml of N-methyl-pyrrolidone (NMP) are added at 5° C. 28 mg of sodiumhydride (NaH; 60% by weight in mineral oil). The mixture is allowed towarm to room temperature and is stirred for 2 hours at this temperature.After cooling to 5° C. 100 mg of methyl iodide (CH₃I) are added. Thestirring is continued for 3 hours at room temperature before water isslowly added. The mixture is then poured into dichloromethane, washedwith water and concentrated to 1 ml before methanol is added. Theprecipitate is collected by Büchner filtration and is washed severaltimes with methanol to yield 180 mg of the DPP derivative of the formula13 as dark blue powder; ¹H-NMR data (ppm, CDCl₃): 8.85 2H s, 7.25 2H d,7.23 2H d, 7.10 2H d, 6.92 2H s, 2.83 4H, d, 2.74 4H d, 1.80-1.85 2H m,1.65-1.67 2H m, 1.24-1.42 32H m, 0.82-0.91 24H m.

EXAMPLE 5 Manufacture of the Semiconducting Compound of the Formula 16

a) A solution of 24.88 g of the 1,4-diketopyrrolo[3,4-c]pyrrole (DPP)derivative of the formula 14, 41 g of K₂CO₃ and 55 g of1-bromo-2-butyl-hexyl (BrBH) in 500 ml of N-methyl-pyrrolidone (NMP) isheated to 140° C. for 6 h. The mixture is washed with water andextracted with dichloromethane. The organic phase is then dried andfiltered on a double layer of silica gel and Hyflo® (Hyflo is used as afilter aid. It is calcined infusorial earth treated with sodiumcarbonate, cf. CAS 91053-39-3 and Fluka 56678) before it isconcentrated. The residue is dissolved in 100 ml of chloroform, cooleddown to 0° C. and 2 equivalents of N-bromosuccinimide are then addedportion wise over a period of 1 h. After the reaction has beencompleted, the mixture is washed with water. The organic phase isextracted, dried and concentrated. The compound is then purified over asilica gel column to give 9.5 g of a violet powder of the DPP derivativeof the formula 15. ¹H-NMR data (ppm, CDCl₃): 8.59, d, 4.1 Hz; 7.21, d,4.1 Hz; 3.91, d; 7.6 Hz; 1.88, m; 1.30, m; 0.86, t, 7.4 Hz. ¹³C NMR(CDCl₃) 161.54; 139.57; 135.40; 131.61; 119.14; 108.28; 46.68; 38.06;31.23; 28.76; 23.39; 14.37.

b) A solution of 2.24 g of the dibrominated DPP derivative of theformula 15, 3.9 g of the tin derivative depicted above, and 351 mg ofPd(PPh₃)₄ in 50 ml of dry toluene is refluxed overnight under inertconditions. After cooling down, the mixture is filtrated on a doublelayer silica gel/Hyflo®, concentrated and precipitated with methanol.The precipitate is filtrated and rinsed with methanol to give 1.56 g ofa blue solid of the DPP derivative of the formula 16; m.p. 139.5° C.;¹H-NMR data (ppm, CDCl₃): 8.85 2H d 4.1 Hz; 7.27 2H d 4.1 Hz; 7.16 2H s;6.92 2H s, 4.03 4H d 7.3 Hz; 2.61 4H m; 2.00 2H m; 1.4 44H m; 0.88 30Hm.

EXAMPLE 6 Application of the Semiconducting Compound of the Formula 16

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 16 obtained in example 5 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed by heating at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and showed clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 3.7×10⁻³ cm²/Vs with an on/off current ratioof 1.7×10⁵ can be determined. The threshold voltage is about 2 V to 4 V.

Electrochemical Measurements

Electrochemical data are obtained by cyclic voltammetry (PrincetonApplied Research-Versastat II) following exactly the same procedure asdescribed in example 2, method B, i.e. the thin-film method. Theresulting level of the DPP derivative of formula 16 corresponds to aHOMO level of approx. −5.5 eV, respectively a LUMO (lowest unoccupiedmolecular orbital) level of −3.8 eV.

EXAMPLE 7 Photovoltaic Application of the Semiconducting Compound ofFormula 16 DPP-Monomer Based Bulk Heterojunction Solar Cell

The solar cell has the following structure: Al (aluminium) electrode/LiF(lithium fluoride) layer/organic layer, including the compound of theformula 16 and the fullerene [60]PCBM/poly(3,4-ethylenedioxy-thiophene)(PEDOT) in admixture with poly(styrenesulfonic acid) (PSS)]/ITO (indiumtin oxide) electrode/glass substrate. The solar cells are made by spincoating a layer of the PEDOT-PSS on a pre-patterned ITO on glasssubstrate. Then a 1:1 mixture by weight of compound 16 (1% by weight inchloroform) and [60]PCBM (a substituted C₆₀ fullerene) (also 1% byweight in chloroform) is spin coated (organic layer). LiF and Al aresublimed under high vacuum through a shadow-mask.

Solar Cell Performance of the Bulk Heterojunction Solar Cell

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=7.1 mA/cm²(milliampere per square centimetre, J_(sc) means short circuit current),FF=0.45 (FF=fill factor) and V_(oc)=0.83 V (V_(oc)=open circuitvoltage), wherefrom an overall efficiency of 2.65% is calculated.

DPP-Monomer Based Bilayer Solar Cell

The bilayer solar cell has the following structure: Al electrode/LiFlayer/[60]PCBM (a substituted C₆₀ fullerene)/organic layer of thecompound 16/poly(3,4-ethylenedioxy-thiophene) (PEDOT) in admixture withpoly(styrenesulfonic acid) (PSS)]/ITO electrode/glass substrate. Thesolar cells are made by spin coating a layer of the PEDOT-PSS on apre-patterned ITO on glass substrate. Then a layer of the compound offormula 16 (1% by weight) is spin coated (organic layer). C₆₀, LiF andAl are sublimed under high vacuum through a shadow-mask.

Solar Cell Performance of the Bilayer Solar Cell

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=0.013 mA/cm², FF=0.26and V_(oc)=0.65 V, wherefrom an overall efficiency of 0.0023% iscalculated.

As evident from a comparison of the above bulk heterojunction solar cellwith the bilayer solar cell the overall solar cell performance of thebulk heterojunction solar cell is much higher.

EXAMPLE 8 Manufacture of the Semiconducting Compound of the Formula 22

a) In a reactor 6.6 g of freshly activated magnesium turnings aresuspended in 250 ml diethyl ether. 50.0 g of compound 17 are addedcarefully. The mixture is stirred first for 2 hours at room temperaturethen refluxed overnight.

Into a second reactor 0.46 g of Ni(dppp)Cl₂ and 20.4 g2,5-dibromothiophene are suspended in 250 ml ether and cooled to 15° C.To this suspension the freshly prepared Grignard solution of 17 is addeddrop wise at such a rate to maintain 20° C. The obtained dark mixture isthereafter stirred at room temperature over night. The reaction isquenched by the addition of 10% HCl. After completion the mixture iswashed with water, dried and concentrated. The compound is purified bydistillation followed by column chromatography on silica gel affording29.9 g of compound 18 as slightly yellow oil.

¹H-NMR data (ppm, CDCl₃): 7.17 2H d, 7.05 2H s, 6.93 2H d, 2.78 4H t,1.65 4H quint, 1.27-1.40 12H m, 0.88 6H t.

b) To a solution of 9.3 g N-formylmethylaniline in 150 ml toluene areadded at 5° C. 19.5 g triflic anhydride, while a white precipitateforms. The reaction mixture is allowed to return to room temperaturebefore 25.0 g of compound 18 are added, dissolved in 100 ml of toluene.The mixture is heated to 110° C. over night. After cooling to roomtemperature 25 ml of a 10% NaOH solution are added. The mixture is thenextracted with water, dried and concentrated. Final purification isachieved by column chromatography on silica gel yielding 20.54 g ofcompound 19 as yellow oil. ¹H-NMR data (ppm, CDCl₃): 9.83 1H s, 7.59 1Hs, 7.23 1H d, 7.21 1H d, 7.10 1H d, 6.95 1H s, 2.82 2H t, 2.76 2H t,1.60-1.74 4H m, 1.30-1.34 12H m, 0.89 3H t, 0.88 3H t.

c) A mixture of 18.5 g of aldehyde 19 and 4.1 g hydroxylamine sulfate in100 mL of dimethyl formamide (DMF) is heated to 145° C. over night.After cooling to room temperature the mixture is diluted with diethylether, washed with water, dried and concentrated. The crude product ispurified by filtration over a silica gel plug under reduced pressureaffording 15.23 g of the desired nitrile 20 as dark oil. ¹H-NMR data(ppm, CDCl₃): 7.44 1H s, 7.21 1H d, 7.14 1H d, 7.08 1H d, 6.95 1H s,2.77 4H t, 1.59-1.69 4H m, 1.27-1.43 12H m, 0.89 3H t, 0.88 3H t.

A mixture of 10 mg FeCl₃, 4.7 g sodium and 200 ml t-amylalcohol isheated to 110° C. for 30 minutes before a mixture of 32.0 g of nitrile20 and 11.7 g ditertamylsuccinate (DTAS) is added drop wise. Thereaction mixture is stirred at 110° C. over night before it is pouredonto a water-methanol mixture. Büchner filtration and exhaustive washingwith methanol affords 28.15 g of the desired DPP derivatives 21 as darkblue powder. ESI-MS m/z (% int.): 965.5 ([M+H]⁺, 100%).

d) To 2.5 g of the 1,4-diketopyrrolo[3,4-c]pyrrole (DPP) derivative 21in 40 ml N-methyl pyrrolidone (NMP) are added 0.3 g NaH (60% in mineraloil) at 5° C. The mixture is allowed to warm to room temperature and isstirred for 2 hours at this temperature. After cooling to 5° C. 1.1 gCH₃I are added. The stirring is continued over night at roomtemperature, then water is slowly added. The mixture is poured indichloromethane, washed with water, concentrated and precipitated withmethanol. The precipitate is collected by Büchner filtration and iswashed several times with methanol to yield 2.37 g of the DPP 22 as darkblue powder. ¹H-NMR data (ppm, CDCl₃): 8.89 2H s, 7.23 2H d, 7.21 2H d,7.10 2H d, 6.95 2H d, 3.66 6H s, 2.89 4H t, 2.80 4H t, 1.64-1.83 8H m,1.33-1.54 24H m, 0.91 6H t, 0.89 6H t.

EXAMPLE 9 Application of the Semiconducting Compound of the Formula 22

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 22 obtained in example 8 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 2000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and showed clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 9.9×10⁻⁵ cm²/Vs with an on/off current ratioof 6.0×10³ can be determined. The threshold voltage is about 0 V to 2 V.

EXAMPLE 10 Manufacture of the Semiconducting Compound of the Formula 23

a) A mixture of 3.0 g of the 1,4-diketopyrrolo[3,4-c]pyrrole (DPP)derivative 21 and 1.7 g K₂CO₃ in 50 ml DMF is heated to 110° C. before1.6 g 1-bromo-3-phenylpropane are added drop wise. The mixture isstirred over night at this temperature. After cooling to roomtemperature, the mixture is poured into dichloromethane, washed withwater, concentrated and precipitated with methanol. The precipitate iscollected by Büchner filtration and washed several times with methanolto yield 3.32 g of the DPP 23 as dark blue powder. ¹H-NMR data (ppm,CDCl₃): 8.84 2H s, 7.21-7.26 10H m, 7.22 2H d, 7.15 2H d, 7.11 2H d,6.96 2H d, 4.16 4H t, 2.77-2.90 12H m, 2.10 4H t, 1.62-1.78 8H m,1.12-1.43 24H m, 0.90 6H t, 0.88 6H t.

EXAMPLE 11 Manufacture of the Semiconducting Compound of the Formula 24

a) According to the procedure for the synthesis of compound 23, 2.0 g ofthe DPP 21 is reacted with 1.3 g 2-ethyl-1-hexyl iodide, 1.1 g K₂CO₃ in50 ml DMF. Purification is achieved by column chromatography over silicagel and precipitation out of chloroform/methanol which affords 1.4 g ofthe desired DPP 24 as blue solid. ¹H-NMR (ppm, CDCl₃): 8.84 2H s, 7.212H d, 7.20 2H d, 7.10 2H d, 6.95 2H d, 4.04 4H d, 2.89 4H t, 2.80 4H t,1.93-1.97 2H m, 1.61-1.79 8H m, 1.28-1.34 40H m, 0.86-0.92 24H m.

EXAMPLE 12 Manufacture of the Semiconducting Compound of the Formula 25

a) According to the procedure for the synthesis of compound 23, 2.0 g ofthe DPP 21 is reacted with 2.9 g 2-hexyl-1-decyl iodide, 1.1 g K₂CO₃ in40 ml DMF. Purification is achieved by column chromatography over silicagel and precipitation out of chloroform/methanol which affords 2.4 g ofthe desired DPP 25 as blue solid.

¹H-NMR data (ppm, CDCl₃): 8.82 2H s, 7.21 2H d, 7.20 2H d, 7.10 2H d,6.95 2H d, 4.05 4H d, 2.89 4H t, 2.80 4H t, 1.95-2.01 2H m, 1.58-1.78 8Hm, 1.23-1.45 72H m, 0.86-0.92 24H m.

EXAMPLE 13 Manufacture of the Semiconducting Compound of the Formula 26

According to the procedure for the synthesis of compound 23, 10.0 g ofthe DPP 21 is reacted with 19.2 g 2-decyl-1-tetradecyl iodide, 5.7 gK₂CO₃ in 200 ml DMF. Purification is achieved by column chromatographyover silica gel and precipitation out of chloroform/methanol whichaffords 8.6 g of the desired DPP 26. ¹H-NMR data (ppm, CDCl₃): 8.84 2Hs, 7.21 2H d, 7.20 2H d, 7.10 2H d, 6.95 2H d, 4.04 4H d, 2.89 4H t,2.80 4H t, 1.93-1.97 2H m, 1.61-1.79 8H m, 1.28-1.34 104H m, 0.84-0.9024H m.

EXAMPLE 14 Manufacture of the Semiconducting Compound of the Formula 32

a) According to the procedure for the synthesis of compound 18, 140 g ofadduct 27 was allowed to react first with 20.7 g magnesium in 300 mldiethyl ether and secondly with 1.4 g Ni(dppp) Cl₂ and 64.4 g2,5-dibromothiopene in 300 ml diethyl ether. Microdestillation atreduced pressure gives 82.7 g of the desired compound 28. ¹H-NMR data(ppm, CDCl₃): 7.17 2H d, 7.05 2H s, 6.93 2H d, 2.79 4H t, 1.65 4H quint,1.40 4H sext, 0.93 6H t.

b) According to the procedure for the synthesis of 19, 60 g of theadduct 28 are reacted with 25.9 g N-formylmethylaniline, 54.0 g triflicanhydride in 500 ml toluene. Column chromatography on silica gel affords51.3 g of the title compound 29. ¹H-NMR data (ppm, CDCl₃): 9.83 1H s,7.60 1H s, 7.24 1H d, 7.21 1H d, 7.10 1H d, 6.95 1H s, 2.84 2H t, 2.802H t, 1.61-1.72 4H m, 1.40-1.46 4H m, 0.97 3H t, 0.95 3H t.

c) According to the procedure for the synthesis of 20, 60.0 g of theadduct 29 are reacted with 13.0 g hydroxylamine sulfate in 200 ml DMF.Filtration over a plug of silica gel affords 50.7 g of the desirednitril 30. ¹H-NMR data (ppm, CDCl₃): 7.44 1H s, 7.21 1H d, 7.15 1H d,7.09 1H d, 6.95 1H s, 2.78 4H t, 1.58-1.69 4H m, 1.34-1.46 4H m, 0.94 3Ht, 0.93 3H t.

d) According to the procedure for the synthesis of 21, 50.0 g of thenitril 30 are reacted with freshly prepared sodium t-amylate (preparedfrom 400 ml t-amylalcohol, 8.4 g sodium and 40 mg FeCl₃) and 21.2 gditertamylsuccinate. Precipitation of the crude DPP from NMP/methanolaffords the desired compound 31 (47.6 g); ESI-MS m/z (% int.): 853.3([M+H]⁺, 100%).

e) According to the procedure for the synthesis of compound 26, 12.5 gof the DPP 31 are reacted with 16.3 g 2-decyl-1-tetradecyl iodide and4.5 g K₂CO₃ in 200 ml DMF. Purification is achieved by columnchromatography over silica gel and precipitation fromchloroform/methanol which affords 3.1 g of the desired DPP 32 as bluesolid. ¹H-NMR data (ppm, CDCl₃): 8.84 2H s, 7.21 2H d, 7.20 2H d, 7.102H d, 6.95 2H d, 4.04 4H d, 2.90 4H t, 2.81 4H t, 1.99-2.01 2H m,1.62-1.78 8H m, 1.30-1.41 88H m, 0.84-1.00 24H m.

EXAMPLE 15 Manufacture of the Semiconducting Compound of the Formula 38

a) In a reactor 13.6 g of 2-bromothiophene is reacted with 2.4 gmagnesium in 100 ml diethyl ether. The mixture is stirred first for 3hours at room temperature then refluxed overnight to give the Grignardsolution. Into a second reactor 1.4 g Ni(dppp)Cl₂[dppp=propane-1,3-diylbis(diphenylphosphane)] and 14.3 g of adduct 33are suspended in 100 ml diethyl ether and cooled to 15° C. To thissuspension the freshly prepared Grignard solution is added drop wise atsuch a rate to keep the mixture below 20° C. The obtained dark mixtureis thereafter stirred at room temperature over night. The reaction isquenched by the addition of 10% HCl. After completion the mixture iswashed with water, dried and concentrated.

Column chromatography purification gave 7.01 g of the desired compound34. ¹H-NMR data (ppm, CDCl₃): 7.32 2H dd, 7.14 2H dd, 7.08 2H dd, 2.724H t, 1.56 4H quint, 1.30-1.45 12H m, 0.92 6H t.

b) According to the procedure for the synthesis of 19, 7.0 g of theadduct 34 is allowed to react with 2.6 g N-formylmethylaniline and 5.5 gtriflic anhydride in 75 ml toluene. Filtration over a silica gel plugaffords 6.2 g of the desired aldehyde 35. ¹H-NMR data (ppm, CDCl₃): 9.881H s, 7.70 1H d, 7.34 1H dd, 7.20 1H d, 7.19 1H dd, 7.08 1H dd, 2.77 2Ht, 2.70 2H t, 1.53-1.58 4H m, 1.28-1.42 12H m, 0.90 3H t, 0.89 3H t;

c) According to the procedure for the synthesis of 20, 6.0 g of thealdehyde 35 is allowed to react with 1.12 g hydroxylamine sulfate in 75ml DMF. Column chromatography affords 4.9 g of the desired nitrile 36.¹H-NMR data (ppm, CDCl₃): 7.57 1H d, 7.35 1H dd, 7.15 1H dd, 7.09 1H dd,7.07 1H d, 2.70 2H t, 2.69 2H t, 1.49-1.57 4H m, 1.28-1.43 12H m, 0.913H t, 0.89 3H t.

d) According to the procedure for the synthesis of 21, 4.8 g of thenitril 36 is allowed to react with freshly prepared sodium t-amylate (75ml t-amylate, 0.7 g sodium and 5 mg FeCl₃) and 1.8 gditertamylsuccinate. Precipitation from NMP and acetone affords 2.9 g ofthe desired DPP 37. ESI-MS m/z (% int.): 965.4 ([M+H]⁺, 100%);

e) According to the procedure for the synthesis of 26, 2.8 g of the DPP37 is allowed to react with 4.1 g 2-decyl-1-tetradecyl iodide and 1.3 gK₂CO₃ in 100 ml DMF. Precipitation from dichloromethane and methanolaffords 2.8 g of the desired DPP 38. ¹H-NMR data (ppm, CDCl₃): 9.03 2Hd, 7.34 2H dd, 7.28 2H d, 7.17 2H dd, 7.08 2H dd, 4.06 4H d, 2.78 4H t,2.71 4H t, 1.94-2.16 2H m, 1.23-1.61 112H m, 0.81-0.93 24H m.

EXAMPLE 16 Manufacture of the Semiconducting Compound of the Formula 44

a) According to the procedure for the synthesis of compound 18, 40.0 gof adduct 39 are reacted first with 4.6 g magnesium in 200 ml diethylether and secondly with 0.3 g Ni(dppp)Cl₂ and 14.3 g 2,5-dibromothiopenein 200 ml diethyl ether. Filtration over silica gel gives 18.3 g of thedesired compound 40. ¹H-NMR data (ppm, CDCl₃): 7.15-7.27 12H m, 6.96 2Hs, 6.94 2H d, 2.82 4H t, 2.68 4H t, 1.99 4H quint.

b) According to the procedure for the synthesis of 19, 18.2 g of theadduct 40 are reacted with 25.8 g N-formylmethylaniline and 12.2 gtriflic anhydride in 150 ml toluene. Column chromatography on silica gelaffords 16.2 g of the title compound 41. ¹H-NMR data (ppm, CDCl₃): 9.831H s, 7.59 1H s, 7.14-7.28 11H m, 7.12 1H d, 6.99 1H d, 6.98 1H d,2.80-2.88 4H m, 2.66-2.74 4H m, 1.96-2.08 4H m.

c) According to the procedure for the synthesis of 20, 16.2 g of theadduct 41 are reacted with 3.1 g hydroxylamine sulfate in 100 ml DMF.Column chromatography affords 10.0 g of the desired nitril 42; ¹H-NMR(ppm, CDCl₃): 7.43 1H s, 7.14-7.28 11H m, 7.04 1H d, 6.97 1H d, 6.95 1Hd, 2.77-2.84 4H m, 2.67 4H t, 1.94-2.04 4H m.

d) According to the procedure for the synthesis of 21, 9.9 g of thenitril 42 are reacted with freshly prepared sodium t-amylate (100 mlt-amylalcohol, 1.3 g sodium and 10 mg FeCl₃) and 3.2 gditertamylsuccinate. Precipitation of the crude DPP from NMP/acetoneaffords the desired DPP 43 (7.2 g); ESI-MS m/z (% int.): 1101.3 ([M+H]⁺,100%).

e) According to the procedure for the synthesis of 25, 3.5 g of the DPP43 are reacted with 4.5 g 2-hexyl-1-decyl iodide, 1.8 g K₂CO₃ in 120 mlDMF. Purification is achieved by precipitation from dichloromethane andmethanol which affords 3.6 g of the desired DPP 44.

¹H-NMR (ppm, CDCl₃): 8.88 2H s, 7.15-7.28 22H m, 7.07 2H d, 6.98 2H d,6.96 2H d, 4.04 4H d, 2.93 4H t, 2.84 4H t, 2.76 4H t, 2.69 4H t,1.94-2.16 8H m, 1.52-1.56 2H m, 1.22-1.34 48H m, 0.81-0.84 12H m.

EXAMPLE 17 Manufacture of the Semiconducting Compound of the Formula 45

a) According to the procedure for the synthesis of 26, 3.5 g of the DPP43 are reacted with 5.9 g 2-decyl-1-tetradecyl iodide and 1.8 g K₂CO₃ in120 ml DMF. Purification is achieved by precipitation fromdichloromethane and methanol which affords 3.1 g of the desired DPP 45.

¹H-NMR (ppm, CDCl₃): 8.89 2H s, 7.15-7.27 22H m, 7.07 2H d, 6.98 2H d,6.96 2H d, 4.04 4H d, 2.93 4H t, 2.84 4H t, 2.76 4H t, 2.69 4H t,1.96-2.15 8H m, 1.52-1.56 2H m, 1.20-1.34 80H m, 0.83-0.87 12H m.

EXAMPLE 18 Manufacture of the Semiconducting Compound of the Formula 50

a) According to the procedure for the synthesis of 18, 18.3 g of adduct17 is allowed to react first with 2.4 g magnesium in 100 ml diethylether and secondly with 0.2 g Ni(dppp)Cl₂, 10.0 g5,5′-dibromo-2,2′-bithiophene in 100 ml diethyl ether. Columnchromatography gives 15.1 g of the desired compound 46. ¹H-NMR (ppm,CDCl₃): 7.17 2H d, 7.11 2H d, 7.01 2H d, 6.93 2H d, 2.78 4H t, 1.67 4Hquint, 1.29-1.35 12H m, 0.89 6H t.

b) According to the procedure for the synthesis of 19, 15.0 g of theadduct 46 are reacted with 4.7 g N-formylmethylaniline and 9.8 g triflicanhydride in 100 ml toluene. Column chromatography on silica gel affords9.1 g of compound 47. ¹H-NMR (ppm, CDCl₃): 9.83 1H s, 7.59 1H s,7.15-7.25 4H m, 7.03 1H d, 6.95 1H d, 2.82 2H t, 2.78 2H t, 1.54-1.72 4Hm, 1.25-1.41 12H m, 0.90 3H t, 0.89 3H t.

c) According to the procedure for the synthesis of 20, 9.1 g of theadduct 47 is reacted with 1.7 g hydroxylamine sulfate in 100 ml DMF.Column chromatography affords 4.9 g of the desired nitril 48. ¹H-NMRdata (ppm, CDCl₃): 7.44 1H s, 7.11-7.20 4H m, 7.03 1H d, 6.95 1H d, 2.784H t, 1.54-1.67 4H m, 1.33-1.43 12H m, 0.88-0.91 6H m.

d) According to the procedure for the synthesis of 21, 4.8 g of thenitril 48 are reacted with freshly prepared sodium t-amylate (50 mlt-amylalcohol, 0.6 g sodium and 5 mg FeCl₃) and 1.5 gditertamylsuccinate. Precipitation of the crude DPP from NMP/methanolaffords the desired compound 49 (3.1 g); ESI-MS m/z (% int.): 1129.3([M+H]⁺, 100%).

e) According to the procedure for the synthesis of 25, 3.0 g of the DPP49 are reacted with 3.7 g 2-hexyl-1-decyl iodide and 1.5 g K₂CO₃ in 80ml DMF. Purification is achieved by column chromatography over silicagel and precipitation from chloroform/methanol which afforded 2.9 g ofthe desired DPP 50. ¹H-NMR (ppm, CDCl₃): 8.82 2H s, 7.14-7.21 8H m, 7.052H d, 6.95 2H d, 4.04 4H d, 2.88 4H t, 2.79 4H t, 1.99-2.01 2H m,1.61-1.82 8H m, 1.24-1.42 104H m, 0.89 12H t. 0.84 12H t.

EXAMPLE 19 Manufacture of the Semiconducting Compound of the Formula 53

a) 228.06 g of 2-decyl-1-tetradecanol [58670-89-6] are mixed with 484.51g 47% hydroiodic acid and the mixture is refluxed overnight. The productis extracted with t-butyl-methylether. Then the organic phase is driedand concentrated. The product is purified over a silica gel column togive 211.54 g of the desired compound 51 (73%). ¹H-NMR (ppm, CDCl₃):3.26 2H d, 1.26-1.12 41H m, 0.88 6H t.

b) According to the procedure for the synthesis of 21, 30.52 g of thenitril [16278-99-2] are reacted with freshly prepared sodium t-amylate(600 ml t-amylalcohol, 10.27 g sodium and 30 mg FeCl₃) and 24.83 gdi-tert-amylsuccinate. Precipitation of the crude DPP from NMP/methanolaffords 33.6 g of the desired compound 52 (90%). MS m/z: 464;

c) According to the procedure for the synthesis of 25, 33.55 g of theDPP 52 are reacted with 74.4 g 2-decyl-1-tetradecyl iodide, 1.27 g LiHin 1300 ml DMF. Purification is achieved by column chromatography oversilica gel and affords 35.1 g of the desired DPP 53 (42.7%). ¹H-NMR(ppm, CDCl₃): 8.91 2H d, 7.35-7.32 6H m, 7.09 2H dd, 4.05 4H d, 1.98 2Hm, 1.35-1.20 80H m, 0.89 6H t, 0.87 6H t.

EXAMPLE 20 Manufacture of the Semiconducting Compound of the Formula 55

a) According to the procedure for the synthesis of 2, 10.00 g 53 aredissolved in 200 ml of chloroform, cooled down to 0° C. and 2equivalents of N-bromosuccinimide (NBS) are then added portion wise overa period of 1 h. After the reaction is completed, the mixture is washedwith water. The organic phase is extracted, dried and concentrated. Thecompound is then purified over a silica gel column to give 5.31 g of adark violet powder of the DPP derivative of the formula 54 (47%). ¹H-NMRdata (ppm, CDCl₃): 8.85 2H d, 7.22 2H d, 7.03 4H dd, 4.00 4H d, 1.93 2Hm, 1.29-1.21 80H m, 0.87 6H t, 0.85 6H t;

b) 1 g of compound 54, 414 mg 2-thienylboronic acid pinacol ester[193978-23-3], 12 mg Pd₂(dba)₃[Tris(dibenzylideneacetone)-di-palladium)] and 9.4 mgtri-tert-butyl-phosphonium-tetrafluoroborate are dissolved in 10 ml oftetrahydrofurane. This solution is degassed with 3 cycles offreeze/pump/thaw (Ar). 0.7 g of potassium phosphate are dissolved in 1.5ml of water and degassed under argon. The water solution is added to theTHF solution and the reaction mixture is refluxed over night. Thereaction mixture is diluted with water and then extracted with methylenechloride. The organic phase is dried and evaporated. The residue ispurified over silica gel and 480 mg of the desired product 55 isobtained as violet solid (50%); m.p. 150° C., ¹H-NMR (ppm, CDCl₃): 8.912H d, 7.29 4H d, 7.21 4H d, 7.12 2H d, 7.03 2H dd, 4.04 4H d, 1.97 2H m,1.33-1.19 80H m, 0.86 6H t, 0.84 6H t.

EXAMPLE 21 Application of the Semiconducting Compound of the Formula 55

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 55 obtained in example 20 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.6×10⁻² cm²/Vs with an on/off current ratioof 1.3×10⁵ is determined. The threshold voltage is about −2 V.

Electrochemical Measurements

Electrochemical data are obtained by cyclic voltammetry followingexactly the same procedure as described in example 2, method B. Theresulting level of the DPP derivative of formula 55 corresponds to aHOMO level of approx. −5.6 eV, respectively a LUMO (lowest unoccupiedmolecular orbital) level of −3.9 eV.

EXAMPLE 22 Photovoltaic Application of the Semiconducting Compound ofFormula 55 DPP-Monomer Based Bulk Heterojunction Solar Cell

The solar cell has the following structure: Al electrode/LiFlayer/organic layer comprising compound 55 and[60]PCBM/[poly(3,4-ethylenedioxy-thiophene) (PEDOT) in admixture withpoly(styrenesulfonic acid) (PSS)]/ITO electrode/glass substrate. Thesolar cells are made by spin coating a layer of the PEDOT-PSS on apre-patterned ITO on glass substrate. Then a 1:1 mixture of the compoundof formula 55 (1% by weight): [60]PCBM (a substituted C₆₀ fullerene) isspin coated (organic layer). LiF and Al are sublimed under high vacuumthrough a shadow-mask.

Solar Cell Performance

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=8.3 mA/cm², FF=0.54and V_(oc)=0.84 V for an estimated overall efficiency of 3.75%.

EXAMPLE 23 Manufacture of the Semiconducting Compound of the Formula 56

According to the procedure for the synthesis of compound 55,2,2′-bithiophene-5-boronic acid pinacol ester [479719-88-5] and compound54 have been reacted to give compound 56; m.p. 196° C.; ¹H-NMR (ppm,CDCl₃): 8.87 2H d, 7.27 2H d, 7.25-7.17 6H m, 7.11-7.08 6H m, 7.02 2Hdd, 4.03 4H d, 1.98 2H m, 1.34-1.18 80H m, 0.86 6H t, 0.84 6H t.

EXAMPLE 24 Application of the Semiconducting Compound of the Formula 56

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 56 obtained in example 23 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.9×10⁻² cm²/Vs with an on/off current ratioof 3.4×10⁵ is determined. The threshold voltage is about 0.7 V and 2 V.

Electrochemical Measurements

Electrochemical data are obtained by cyclic voltammetry followingexactly the same procedure as described in example 2, method B.

The resulting level of the DPP derivative of formula 56 corresponds to aHOMO level of approx. −5.6 eV, respectively a LUMO (lowest unoccupiedmolecular orbital) level of −4.0 eV.

EXAMPLE 25 Photovoltaic Application of the Semiconducting Compound ofFormula 56 DPP-Monomer Based Bulk Heterojunction Solar Cell

The solar cell has the following structure: Al electrode/LiFlayer/organic layer, comprising compound 56 and[60]PCBM/[poly(3,4-ethylenedioxy-thiophene) (PEDOT) in admixture withpoly(styrenesulfonic acid) (PSS)]/ITO electrode/glass substrate. Thesolar cells are made by spin coating a layer of the PEDOT-PSS on apre-patterned ITO on glass substrate. Then a 1:1 mixture of the compoundof formula 56 (1% by weight): [60]PCBM (a substituted C₆₀ fullerene) isspin coated (organic layer). LiF and Al are sublimed under high vacuumthrough a shadow-mask.

Solar Cell Performance

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=10.5 mA/cm², FF=0.55and V_(oc)=0.76 V for an estimated overall efficiency of 4.4%.

EXAMPLE 26 Manufacture of the Semiconducting Compound of the Formula 58

a) 370.1 ml 1.6 M n-BuLi (n-butyl lithium) is added under argon dropwise to a solution of 67.5 g diisopropylamine in 550 ml THF at −78° C.After stirring at −78° C. for 30 minutes the mixture is allowed to reach0° C. where the stirring is continued for 2 hours, then the mixture iscooled to −78° C. 100.0 g 3-phenylpropylthiophene [120245-35-4] are thenadded drop wise and after 2 hours stirring 115.0 g2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane [61676-62-8] areadded dropwise. The reaction mixture is stirred at −78° C. foradditional 30 minutes and is then gradually warmed to room temperatureand stirred overnight. The solution is poured on 750 ml 1 N HCl. Theorganic part is extracted with 900 ml ethyl acetate and is washed with300 ml water. The organic layer is dried over Na₂SO₄ and the solventsare removed under reduced pressure. Column chromatography over silicagel gives 130.4 g of the desired compound 57: ¹H-NMR (ppm, CDCl₃): 7.481H s, 7.30-7.26 2H m, 7.23 1H s, 7.20-7.16 3H m, 2.67 2H t, 2.64 2H t,1.96 2H quint, 1.34 12H s.

b) According to the procedure for the synthesis of compound 55,4-(phenylpropyl)-thiophene-2-boronic acid pinacol ester 57 and compound54 are reacted to give compound 58: ¹H-NMR (ppm, CDCl₃): 8.91 2H d,7.32-7.17 14H m, 7.06 2H d, 7.03 2H s, 6.85 2H s, 4.03 4H d, 2.68 4H t,2.63 4H t, 2.03-1.93 6H m, 1.33-1.19 80H m, 0.85 6H t, 0.83 6H t.

EXAMPLE 27 Application of the Semiconducting Compound of the Formula 58

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 58 obtained in example 26 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and showed clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.1×10⁻⁴ cm²/Vs with an on/off current ratioof 1.7×10⁴ can be determined. The threshold voltage is about −5 V and −3V.

EXAMPLE 28 Manufacture of the Semiconducting Compound of the Formula 59

According to the procedure for the synthesis of compound 55,phenyl-boronic acid pinacol ester [24388-23-6] and compound 54 arereacted to give compound 59; m.p. 158° C.; ¹H-NMR data (ppm, CDCl₃):8.93 2H d, 7.61 4H d, 7.40 4H t, 7.33-7.26 8H m, 4.04 4H d, 1.98 2H m,1.33-1.19 80H m, 0.87 6H t, 0.85 6H t.

EXAMPLE 28a Application of the Semiconducting Compound of the Formula 59

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 59 obtained in example 28 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and showed clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 5.2×10⁻³ cm²/Vs with an on/off current ratioof 1.2×10⁵ can be determined. The threshold voltage is of about −3 V.

EXAMPLE 29 Manufacture of the Semiconducting Compound of the Formula 60

According to the procedure for the synthesis of compound 55,4-biphenyl-boronic acid pinacol ester [144432-80-4] and compound 54 arereacted to give compound 60; m.p. 230° C.; ¹H-NMR (ppm, CDCl₃): 8.89 2Hd, 7.67 4H d, 7.66-7.60 4H m, 7.43 4H dd, 7.36-7.29 4H m, 7.24 4H s,4.04 4H d, 1.99 2H m, 1.35-1.19 80H m, 0.85 6H t, 0.83 6H t.

EXAMPLE 29a Application of the Semiconducting Compound of the Formula 60

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 60 obtained in example 29 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and showed clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.3×10⁻² cm²/Vs with an on/off current ratioof 2.0×10⁵ can be determined. The threshold voltage is of about −6 V to−1.5 V.

Solar Cell Performance of the Bulk Heterojunction Solar Cell

The bulk heterojunction solar cell described in Example 7 wherein thecompound of the formula 16 is replaced by compound 60 is measured undera solar light simulator. Then with the External Quantum Efficiency (EQE)graph the current is estimated under AM1.5 conditions. This leads to avalue of J_(sc)=4.8 mA/cm², FF=0.59, V_(oc)=0.80 V and an overallefficiency of about 2.2%.

EXAMPLE 30 Manufacture of the Semiconducting Compound of the Formula 61

According to the procedure for the synthesis of compound 55,5′-hexyl-2,2′-bithiophene-5-boronic acid pinacol ester [579503-59-6] andcompound 54 are reacted to give compound 61; m.p. 135° C.; ¹H-NMR (ppm,CDCl₃): 8.93 2H d, 7.25 2H d, 7.16 2H d, 7.04 4H dd, 6.97 4H dd, 6.67 2Hd, 4.01 4H d, 2.79 4H t, 1.96 2H m, 1.67 4H txt, 1.34-1.18 92H m, 0.906H t, 0.86 6H t, 0.85 6H t.

EXAMPLE 31 Application of the Semiconducting Compound of the Formula 61

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 61 obtained in example 30 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 3.4×10⁻³ cm2/Vs with an on/off current ratioof 6.4×10⁴ is determined. The threshold voltage is about −0.5 V to 2 V.

EXAMPLE 32 Photovoltaic Application of the Semiconducting Compound ofFormula 61 DPP-Monomer Based Bulk Heterojunction Solar Cell

The solar cell has the following structure: Al electrode/LiFlayer/organic layer, including the compound of the formula 61 and thefullerene [60]PCBM/poly(3,4-ethylenedioxy-thiophene) (PEDOT) inadmixture with poly(styrenesulfonic acid) (PSS)]/ITO electrode/glasssubstrate. The solar cells are made by spin coating a layer of thePEDOT-PSS on a pre-patterned ITO on glass substrate. Then a 1:1 mixtureby weight of compound 16 (1% by weight in chloroform) and [60]PCBM (asubstituted C₆₀ fullerene) (also 1% by weight in chloroform) is spincoated (organic layer). LiF and Al are sublimed under high vacuumthrough a shadow-mask.

Solar Cell Performance

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=2.2 mA/cm², FF=0.66and V_(oc)=0.74 V for an estimated overall efficiency of 1.1%.

EXAMPLE 33 Manufacture of the Semiconducting Compound of the Formula 63

a) According to the procedure for the synthesis of compound 52,5-Cyano-2,2′:5′,2″-Terthiophene [110230-97-2] is reacted to giveinsoluble compound 62: MS m/z: 628.

b) According to the procedure for the synthesis of 53, the DPP 62 isreacted with iodomethane [74-88-4] to give insoluble (i.e. insoluble inchloroform/toluene) compound 63. MS m/z: 656.

EXAMPLE 34 Manufacture of the Semiconducting Compound of the Formula 64

According to the procedure for the synthesis of 53, the DPP 62 isreacted with 2-ethyl-hexyl iodide [1653-16-3] to give compound 64.¹H-NMR (ppm, CDCl₃): 8.94 2H d, 7.28-7.21 8H m, 7.12 2H d, 7.05 2H dd,4.05 4H d, 1.94 2H m, 1.45-1.23 16H m, 0.93 6H t, 0.91 6H t.

EXAMPLE 35 Manufacture of the Semiconducting Compound of the Formula 67

a) According to the procedure for the synthesis of compound 57,3-butyl-thiophene [34722-01-5] and2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxoborolane [61676-62-8] arereacted to give compound 65: ¹H-NMR (ppm, CDCl₃): 7.47 1H s, 7.21 1H s,2.65 2H t, 1.63 2H quint, 1.38-1.31 2H m, 1.34 12H s, 0.91 3H t.

b) According to the procedure for the synthesis of compound 55,4-butyl-2-thiophene-boronic acid pinacol ester 65 and the DPP derivative66 (Example 2 of WO 2008/000664) are reacted to give compound 67: ¹H-NMR(ppm, CDCl₃): 8.79 2H d, 7.19 2H d, 7.07 2H s, 6.84 2H s, 3.96 4H d,2.54 4H t, 1.89 2H m, 1.61-1.14 56H m, 0.88 6H t, 0.77 6H t, 0.75 6H t.

EXAMPLE 36 Manufacture of the Semiconducting Compound of the Formula 68

According to the procedure for the synthesis of compound 55,4-(phenylpropyl)-2-thiophene-boronic acid pinacol ester 57 and the DPPderivative 66 (Example 2 of WO 2008/000664) are reacted to give compound68: ¹H-NMR (ppm, CDCl₃): 8.79 2H d, 7.25-7.09 12H m, 7.06 2H s, 6.84 2Hs, 3.94 4H d, 2.63-2.54 8H m, 1.96-1.86 6H m, 1.29-1.13 48H m, 0.76 6Ht, 0.74 6H t.

EXAMPLE 37 Manufacture of the Semiconducting Compound of the Formula 69

According to the procedure for the synthesis of compound 55,4-methyl-2-thiophene-boronic acid pinacol ester [635305-48-5] and theDPP derivative 66 (Example 2 of WO 2008/000664) are reacted to givecompound 69: ¹H-NMR (ppm, CDCl₃): 8.79 2H d, 7.19 2H d, 7.06 2H s, 6.832H s, 3.96 4H d, 2.21 6H s, 1.89 2H m, 1.31-1.14 48H m, 0.77 6H t, 0.756H t.

EXAMPLE 38 Manufacture of the Semiconducting Compound of the Formula 70

According to the procedure for the synthesis of compound 55,5′-hexyl-2,2′-bithiophene-5-boronic acid pinacol ester [579503-59-6] and66 are reacted to give compound 70: ¹H-NMR (ppm, CDCl₃): 8.92 2H d, 7.282H d, 7.20 2H d, 7.04 4H dd, 6.71 2H d, 4.04 4H d, 2.81 4H t, 1.98 2H m,1.67 4H m, 1.34-1.24 60H m, 0.92-0.82 18H m.

EXAMPLE 39 Application of the Semiconducting Compound of the Formula 70

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 70 obtained in example 38 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 8.7×10⁻⁴ cm²/Vs with an on/off current ratioof 2.9×10⁴ is determined. The threshold voltage is about −5 V and −3 V.

EXAMPLE 40 Manufacture of the Semiconducting Compound of the Formula 74

a) According to the procedure for the synthesis of compound 55,thiophene-2-boronic acid pinacol ester [193978-23-3] and 66 are reactedto give compound 71: ¹H-NMR (ppm, CDCl₃): 8.90 2H d, 7.34-7.32 6H m,7.08 2H dd, 4.04 4H d, 1.98 2H m, 1.35-1.20 48H m, 0.87-0.81 12H m.

b) According to the procedure for the synthesis of compound 54, compound71 and N-bromosuccinimide (NBS) are reacted to give compound 71: ¹H-NMRdata (ppm, CDCl₃): 8.86 2H d, 7.27 2H d, 7.04 4H dd, 4.01 4H d, 1.94 2Hm, 1.32-1.21 48H m, 0.87-0.85 12H m.

c) According to the procedure for the synthesis of compound 57,(S)-3-(3,7-dimethyloctyl)-thiophene [176261-80-6] and2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxoborolane [61676-62-8] arereacted to give compound 75: ¹H-NMR (ppm, CDCl₃): 7.50 1H s, 7.23 1H s,2.65 2H m; 1.70-1.10 68 10H m, 1.36 12H s, 0.93 3H d, 0.88 6H d.

d) According to the procedure for the synthesis of compound 55,compounds 72 and 73 are reacted to give compound 74; m.p. 102.5° C.;¹H-NMR (ppm, CDCl₃): 8.92 2H d, 7.9 2H d, 7.21 2H d; 7.10 2H d, 7.06 2Hs, 6.85 2H s, 4.05 4H d; 2.60 4H m; 1.98 2H m; 1.35-1.20 68H m 0.93 6Hd, 0.89-0.81 24H m.

EXAMPLE 41 Application of the Semiconducting Compound of the Formula 74

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 74 obtained in example 40 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.3×10⁻⁴ cm²/Vs with an on/off current ratioof 9.1×10³ is determined. The threshold voltage is about 1.7V.

EXAMPLE 42 Manufacture of the Semiconducting Compound of the Formula 76

a) According to the procedure for the synthesis of compound 2, compound1 and (S)-3-3,7-dimethyloctyl-bromide [79434-89-2] are reacted in DMF(instead of NMP) followed by the bromination with N-bromosuccinimide(NBS) yielding compound 75. ¹H-NMR (ppm, CDCl₃): 8.65 2H d, 7.23 2H d,4.02 4H m, 1.72-1.10 20H m, 1.00 6H d, 0.86 12H d.

b) According to the procedure for the synthesis of compound 55,2,2′-bithiophene-5-boronic acid pinacol ester [479719-88-5] and compound75 are reacted to give compound 76; m.p. 239.8° C.; ¹H-NMR (ppm, CDCl₃):8.94 2H d, 7.31 2H d, 7.27 2H d, 7.23 4H dd, 7.13 2H d, 7.05 2H dd, 4.134H m, 1.75-1.10 20H m, 1.05 6H d, 0.85 12H d.

EXAMPLE 43 Application of the Semiconducting Compound of the Formula 76

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 76 obtained in example 42 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 6.5×10⁻⁴ cm²/Vs with an on/off current ratioof 4.1×10⁴ is determined. The threshold voltage is about 1.6V.

EXAMPLE 44 Photovoltaic Application of the Semiconducting Compound ofFormula 76 DPP-Monomer Based Bulk Heterojunction Solar Cell

The solar cell has the following structure: Al electrode/LiFlayer/organic layer, including compound 76 and[60]PCBM/[poly(3,4-ethylenedioxy-thiophene) (PEDOT)/poly(styrenesulfonicacid) (PSS)]/ITO electrode/glass substrate. The solar cells are made byspin coating a layer of the PEDOT-PSS on a pre-patterned ITO on glasssubstrate. Then a 1:1 mixture of the compound of formula 76 (1% byweight): [60]PCBM (a substituted C₆₀ fullerene) is spin coated (organiclayer). LiF and Al are sublimed under high vacuum through a shadow-mask.

Solar Cell Performance

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=7.7 mA/cm², FF=0.34and V_(oc)=0.70 V for an estimated overall efficiency of 1.8%.

EXAMPLE 45 Manufacture of the Semiconducting Compound of the Formula 77

According to the procedure for the synthesis of compound 55,1-benzothien-2-ylboronic acid [162607-15-0] and compound 75 are reactedto give compound 77; m.p. 275.0° C.; ¹H-NMR (ppm, CDCl₃): 8.95 2H d,7.31 2H d, 7.79 4H m, 7.55 2H s, 7.44 2H d, 7.37 4H m, 4.16 4H m,1.85-1.10 20H m, 1.06 6H d, 0.85 12H d.

EXAMPLE 46 Application of the Semiconducting Compound of the Formula 77

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 77 obtained in example 45 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.8×10⁻³ cm²/Vs with an on/off current ratioof 2.7×10⁴ is determined. The threshold voltage is about −4 V to 0 V.

EXAMPLE 47 Photovoltaic Application of the Semiconducting Compound ofFormula 77 DPP-Monomer Based Bulk Heterojunction Solar Cell

The solar cell has the following structure: Al electrode/LiFlayer/organic layer, including compound 77 and[60]PCBM/[poly(3,4-ethylenedioxy-thiophene) (PEDOT)/poly(styrenesulfonicacid) (PSS)]/ITO electrode/glass substrate. The solar cells are made byspin coating a layer of the PEDOT-PSS on a pre-patterned ITO on glasssubstrate. Then a 1:1 mixture of the compound of formula 77 (1% byweight): [60]PCBM (a substituted C₆₀ fullerene) is spin coated (organiclayer). LiF and Al are sublimed under high vacuum through a shadow-mask.

Solar Cell Performance

The solar cell is measured under a solar light simulator. Then with theExternal Quantum Efficiency (EQE) graph the current is estimated underAM1.5 conditions. This leads to a value of J_(sc)=1.1 mA/cm², FF=0.30and V_(oc)=0.25 V.

EXAMPLE 48 Manufacture of the Semiconducting Compound of the Formula 78

According to the procedure for the synthesis of compound 55,5′-hexyl-2,2′-bithiophene-5-boronic acid pinacol ester [579503-59-6] andcompound 75 are reacted to give compound 77: ¹H-NMR (ppm, CDCl₃): 8.942H d, 7.27 2H d, 7.19 2H d, 7.02 4H dd, 6.70 2H d, 4.13 4H m, 2.80 4H t,1.81-1.20 36H m, 1.05 6H d, 0.91 6H t, 0.85 12H d.

EXAMPLE 49 Application of the Semiconducting Compound of the Formula 78

The semiconductor thin film is prepared either by spin-coating or dropcasting the DPP derivative of the formula 78 obtained in example 48 in a0.5% (w/w) solution in chloroform. The spin coating is accomplished at aspinning speed of 3000 rpm (rounds per minute) for about 20 seconds inambient conditions. The devices are evaluated as deposited and afterbeing annealed at 100° C. for 15 minutes.

Transistor Performance

The transistor behavior is measured on an automated transistor prober(TP-10, CSEM Zürich) and shows clear p-type transistor behavior. From alinear fit to the square root of the saturated transfer characteristicsa field effect mobility of 1.8×10⁻³ cm²/Vs with an on/off current ratioof 1.9×10⁴ is determined. The threshold voltage is about −0.5 V.

EXAMPLE 50 Manufacture of the Semiconducting Compound of the Formula 80

a) Analogous to the procedure for the synthesis of compound 54, compound58 is dissolved in chloroform, cooled down to 0° C. and 2 equivalents ofN-bromosuccinimide (NBS) are then added portion wise over a period of 1h. After the reaction is completed, the mixture is washed with water.The organic phase is extracted, dried and concentrated. The compound isthen purified over a silica gel column to give the compound of theformula 79; ¹H-NMR (ppm, CDCl₃): 8.90 2H broad s, 7.33-7.15 14H m, 7.002H d, 6.87 2H s, 4.00 4H d, 2.69 4H dxd, 2.59 4H dxd, 2.00-1.90 6H m,1.33-1.21 80H m, 0.87 6H t, 0.85 6H t.

Analogous to the procedure for the synthesis of compound 55,2,2′:5′,2″-terthiophene-5-boronic acid pinacol ester [849062-17-5] andcompound 79 are reacted to give compound 80; ¹H-NMR (ppm, CDCl₃): 8.932H d, 7.33-6.89 32H m, 4.00 4H d, 2.78-2.71 8H m, 2.05-1.97 6H m,1.34-1.18 80H m, 0.85 12H t.

Transistor Performance

The transistor behavior of compound 80 is measured on an automatedtransistor prober (TP-10, CSEM Zürich) and shows clear p-type transistorbehavior. From a linear fit to the square root of the saturated transfercharacteristics a field effect mobility of 1.3×10⁻² cm²/Vs with anon/off current ratio of 1×10⁵ can be determined. The threshold voltageis about 10 V.

EXAMPLE 51 Manufacture of the Semiconducting Compounds of the Formulae81 to 85

Using the methods described herein before the following compounds areobtained:

EXAMPLE 51a

EXAMPLE 51b

EXAMPLE 51c

EXAMPLE 51d

EXAMPLE 51e

EXAMPLE 51f

EXAMPLE 51g

EXAMPLE 51h

EXAMPLE 51i

1. A compound of the formula I

wherein R¹ and R² are independently of each other an aliphatic,cycloaliphatic, cycloaliphatic-aliphatic, aromatic, aromatic-aliphatic,heteroaromatic or heteroaromatic-aliphatic group having up to 49 carbonatoms, a and d independently of each other are 0, 1, 2 or 3, Ar¹ and Ar⁴are independently of each other a bivalent group of the formula II or IV

wherein R⁶ and R⁷ are as defined below, p represents 0, 1, or 2, R⁵ isan aliphatic hydrocarbon group having up to 25 carbon atoms, or twovicinal groups R⁵ together represent alkylene or alkenylene having up to7 carbon atoms, it being possible that two groups R⁵ present in thegroup of formula II differ from each other, b, c, e, and f independentlyof each other represent 1, 2 or 3, Ar², Ar³, Ar⁵, and Ar⁶ areindependently of each other a bivalent group of one of the formulae IVto X and L,

wherein R⁶, R⁷, R⁸, R⁹, R¹², R¹³, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹are independently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, or heteroaryl, or R⁶ and R⁷ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms, R¹⁶ and R¹¹ are independently of each other hydrogen,C₁-C₁₈alkyl, C₆-C₂₄aryl, heteroaryl, or R¹⁰ and R¹¹ together representoxo or form a five or six membered ring, which is unsubstituted orsubstituted by a) an aliphatic hydrocarbon group having up to 18 carbonatoms, b) C₁-C₁₈alkoxy or C₂-C₁₈alkylenedioxy in both of which carbonatoms which are not adjacent to oxygen may be replaced by oxygen, or c)C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, C₃-C₁₂cycloalkyl orC₄-C₁₂cycloalkyl-alkyl, and R³ and R⁴ are independently of each other agroup of one of the formulae XI to XIX,

wherein R²² to R²⁶ and R²⁹ to R⁵⁸ represent independently of each otherhydrogen, an aliphatic hydrocarbon group having up to 25 carbon atoms,alkoxy or alkenyloxy having up to 18 carbon atoms, halogen, acycloaliphatic, cycloaliphatic-aliphatic, aromatic, aromatic-aliphatic,heteroaromatic or heteroaromatic-aliphatic group having up to 25 carbonatoms, or a group of the formula (III)

wherein R represents an aliphatic hydrocarbon group having up to 12carbon atoms, or two groups R²² to R²⁶ and R²⁹ to R⁵⁷ which are in theneighborhood of each other, together represent alkylene or alkenylenehaving up to 8 carbon atoms, thereby forming a ring, and R²⁷ and R²⁸ areindependently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₅-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, or a group of the formula (III)shown above, wherein R represents an aliphatic hydrocarbon group havingup to 12 carbon atoms, or R²⁷ and R²⁸ together or R²⁷ and R⁵⁸ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms.
 2. A compound of the formula I according to claim 1wherein R¹ and R² are independently of each other an aliphatic,cycloaliphatic, cycloaliphatic-aliphatic, aromatic, aromatic-aliphatic,heteroaromatic or heteroaromatic-aliphatic group having up to 25 carbonatoms, R³ and R⁴ are independently of each other a group of one of theformulae XI to XIX,

wherein R²² to R²⁶ and R²⁹ to R⁵⁸ represent independently of each otherhydrogen, an aliphatic hydrocarbon group having up to 25 carbon atoms,or a group of the formula (III)

wherein R represents an aliphatic hydrocarbon group having up to 12carbon atoms, or two groups R²² to R²⁶ and R²⁹ to R⁵⁷ which are in theneighborhood of each other, together represent alkylene or alkenylenehaving up to 8 carbon atoms, thereby forming a ring, and R²⁷ and R²⁸ areindependently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, or a group of the formula (III)shown above, wherein R represents an aliphatic hydrocarbon group havingup to 12 carbon atoms, or R²⁷ and R²⁸ together or R²⁷ and R⁵⁸ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms, and the remaining substituents are as defined in claim 1.3. A compound of the formula I according to claim 1 wherein R¹ and R²are independently of each other an aliphatic, cycloaliphatic orcycloaliphatic-aliphatic hydrocarbon group having up to 25 carbon atoms,a and d represent 0, b, c, e, and f represent 1, Ar², Ar³, Ar⁵, and Ar⁶are independently of each other a bivalent group of the formula IV,

wherein R⁶ and R⁷ are independently of each other hydrogen orC₁-C₂₅alkyl, and R³ and R⁴ are independently of each other a group ofthe formula

wherein R⁵⁸ represents hydrogen or an aliphatic hydrocarbon group havingup to 25 carbon atoms, and R²⁷ and R²⁸ are independently of each otherhydrogen or C₁-C₂₅alkyl.
 4. A compound of the formula I according toclaim 1 wherein R¹ and R² are independently of each other an aliphatic,cycloaliphatic or cycloaliphatic-aliphatic hydrocarbon group having upto 25 carbon atoms, a and d represent 0, b, c, e, and f represent 1, Ar²and Ar⁵ are independently of each other a bivalent group of the formulaIV,

wherein one of R⁶ and R⁷ represents C₁-C₂₅alkyl while the other of R⁶and R⁷ represents hydrogen or C₁-C₂₅alkyl, Ar³ and Ar⁶ are a bivalentgroup of the formula IV, wherein each of R⁶ and R⁷ represents hydrogen,and R³ and R⁴ are independently of each other a group of the formula

wherein R⁵⁸ represents hydrogen or an aliphatic hydrocarbon group havingup to 25 carbon atoms, and one of R²⁷ and R²⁸ represents C₁-C₂₅alkylwhile the other of R²⁷ and R²⁸ represents hydrogen or C₁-C₂₅alkyl.
 5. Acompound of the formula I according to claim 1 wherein R¹ and R² areindependently of each other an alkyl group having up to 49 carbon atoms,a and d are independently of each other 0, 1 or 2, Ar¹ and Ar⁴ areindependently of each other a bivalent group of the formula IV

wherein R⁶ and R⁷ are independently of each other hydrogen orC₁-C₂₅alkyl, b, c, e, and f independently of each other represent 1, 2or 3 Ar², Ar³, Ar⁵, and Ar⁶ are independently of each other a bivalentgroup of the formula IV,

wherein R⁶ and R⁷ are independently of each other hydrogen, C₁-C₂₅alkyl,or C₇-C₂₅aralkyl, and R³ and R⁴ are independently of each other a groupof one of the formulae XI to XIII, XV, XVI and XIX

wherein R²² to R²⁶, R²⁹ to R³³, R⁴¹ to R⁵⁶, R⁵⁷ and R⁵⁸ representindependently of each other hydrogen, an aliphatic hydrocarbon grouphaving up to 25 carbon atoms, aryl, alkoxy having up to 18 carbon atoms,or halogen, or two groups R²² to R²⁶ which are in the neighborhood ofeach other, together represent alkylene or alkenylene having up to 8carbon atoms, thereby forming a ring, and R²⁷ and R²⁸ are independentlyof each other hydrogen, C₁-C₂₅alkyl, or C₇-C₂₅aralkyl, or R²⁷ and R²⁸together represent alkylene or alkenylene which may be both bonded viaoxygen and/or sulfur to the thienyl residue and which may both have upto 25 carbon atoms.
 6. A compound of the formula I according to claim 1wherein R¹ and R² have the same meaning and the side chains of theformulae XLV and XLVI are identical to each other.


7. A compound of the formula I according to claim 1 selected from thecompounds having the following formulae


8. A compound of the formula I according to claim 1 selected from thecompounds having the following formulae


9. A semiconductor device comprising as a semiconducting effective meansa compound of the formula I

wherein R¹ and R² are independently of each other an aliphatic grouphaving 7 to 25 carbon atoms, or a cycloaliphatic,cycloaliphatic-aliphatic, aromatic, aromatic aliphatic, heteroaromaticor heteroaromatic-aliphatic group having up to 25 carbon atoms, a and dindependently of each other are 0, 1, 2 or 3, Ar¹ and Ar⁴ areindependently of each other a bivalent group of the formula II or IV

wherein R⁶ and R⁷ are as defined below, p represents 0, 1, or 2, R⁵ isan aliphatic hydrocarbon group having up to 25 carbon atoms, or twovicinal groups R⁵ together represent alkylene or alkenylene having up to7 carbon atoms, it being possible that two groups R⁵ present in thegroup of formula II differ from each other, b and e independently ofeach other represent 1, 2 or 3, c and f independently of each otherrepresent 0, 1, 2 or 3, Ar², Ar³, Ar², and Ar⁶ are independently of eachother a bivalent group of one of the formulae IV to X and L,

wherein R⁶, R⁸, R⁹, R¹², R¹³, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰ and R²¹ areindependently of each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy,C₆-C₂₄aryl, C₇-C₂₅aralkyl, or heteroaryl, or R⁶ and R⁷ togetherrepresent alkylene or alkenylene which may be both bonded via oxygenand/or sulfur to the thienyl residue and which may both have up to 25carbon atoms, R¹⁰ and R¹¹ are independently of each other hydrogen,C₁-C₁₈alkyl, C₆-C₂₄aryl, heteroaryl, or R¹⁰ and R¹¹ together representoxo or form a five or six membered ring, which is unsubstituted orsubstituted by a) an aliphatic hydrocarbon group having up to 18 carbonatoms, b) C₁-C₁₈alkoxy or C₂-C₁₈alkylenedioxy in both of which carbonatoms which are not adjacent to oxygen may be replaced by oxygen, or c)C₆-C₂₄aryl, C₇-C₂₅aralkyl, heteroaryl, C₃-C₁₂cycloalkyl orC₄-C₁₂cycloalkyl-alkyl, and R³ and R⁴ are independently of each other agroup of one of the formulae XI to XIX,

wherein R²² to R²⁶ and R²⁹ to R⁵⁸ represent independently of each otherhydrogen, an aliphatic hydrocarbon group having up to 25 carbon atoms,or two groups R²² to R²⁶ and R²⁹ to R⁵⁷ which are in the neighborhood ofeach other, together represent alkylene or alkenylene having up to 8carbon atoms, thereby forming a ring, and R²⁷ and R²⁸ are independentlyof each other hydrogen, C₁-C₂₅alkyl, C₁-C₁₈alkoxy, C₆-C₂₄aryl,C₇-C₂₅aralkyl, heteroaryl, or R²⁷ and R²⁸ together or R²⁷ and R⁵⁸together represent alkylene or alkenylene which may be both bonded viaoxygen and/or sulfur to the thienyl residue and which may both have upto 25 carbon atoms.
 10. A semiconductor device according to claim 9comprising as a semiconducting effective means a compound of the formulaI as defined in claim 9 with the proviso that at least one of R⁶, R⁷,R²⁷, R²⁸ and R⁵⁸ is different from hydrogen.
 11. A semiconductor deviceaccording to claim 9 comprising as a semiconducting effective means acompound of the formula I according to claim 9 selected from thecompounds having the following formulae


12. A semiconductor device according to claim 9 in the form of a diode,a photodiode, a sensor, an organic field effect transistor, a transistorfor flexible displays, or a heterojunction solar cell.
 13. A p-typetransistor comprising the compound of formula I as defined in claim 1.